First type of route you have driven

[national highway 1]

Simple. Name the first route you have driven for each type of route:
Interstate (2di or 3di)
US Route (2dus or 3dus)
State/Provincial Route
County Route

Since I live in New South Wales, Australia, where, since 2013 has started switching over to a British-style M/A/B Alphanumeric Route number scheme and I only have started my Learner's Driving, I haven't had much experience in travelling the state's highway network yet.
I'll make a start:
M Route- M4
A Route- A28
B Route- B83

[jakeroot]

I don't normally jump into these listing threads, but fuck it:

Interstate: I-5
US Route: Probably US-12 -- there aren't any US Routes in the area that I regularly drive
State Route: WA-512 Freeway (the day I got my learners permit)
Provincial Route: BC-99 (coming up the I-5)
County Route: Never driven on a county route.

[CNGL-Leudimin]

Here are mine:
Freeway/expressway ('Interstate'): A-23.
National road ('US Route'): N-330.
Regional road ('State Route'): A-1212 (Second-tier, the very first time I was behind the wheel).
Provincial road ('County Route'): Not sure, probably HU-V-5231 (unsigned).

[DandyDan]

Freeway/Interstate-  The first freeway I drove on was the US 20 bypass of Elgin, Illinois, when I still had my learners permit.  As for interstate highways, I got to drive on I-290 once on my permit.
US Route- US 34, followed quickly by US 30 by Aurora, IL
State Route- Illinois Route 64 in St. Charles, IL (my old hometown)
County road- Not sure what constitutes a county road for sure for the Fox Valley of Illinois.  Probably Dunham Road or Kirk Road in St. Charles.

[Eth]

Most of this is surprisingly fuzzy...

Interstate - I'm about 90% sure it was I-285. If not that, then it was I-75.
US Route - US 29
State Route - GA 8 (at the same time as US 29, natch)
County Road - This is my least certain one. I think it's Holmes CR 173 in Florida, but there are a few other potential candidates in that county (and also in Washington County and in Geneva County, AL).

[SD Mapman]

Interstate: I-90
US Route: US 14, but my first standalone was US 85
State Route: WY 111
County Route: CR 543 (Lawrence County)

[jp the roadgeek]

It's been a while, so these are probable

Interstate: I-84 (or I-691)
US Route: US 5 (or US 6 when multiplexed with I-84)
State Route: CT 364
County Route (tough, since there aren't any in CT): CR 64 in Orange County, NY

[TravelingBethelite]

Questionable about the 'driven' part, but I'll give it a shot:

Interstate: I-84
US Route: US 6
State Route: CT 302 (runs right near my subdivision)
County Route: CR K-546, Douglas County, Missouri

[dgolub]

Interstate: Long Island Expressway (I-495)
US Route: Boston Post Road (US 1)
State Route: Port Washington Boulevard (NY 101)
County Route: West Shore Road (Nassau CR 15)
Signed County Route: Nicolls Road (Suffolk CR 97)

All Long Island stuff, except for US 1, since there are no US routes on Long Island.

[pumpkineater2]

Interstate: I-8 between Yuma and Gila bend, AZ
US Route: A few short miles on US-60 the day I got my license. I haven't personally driven on any US route since then, over a year and a half ago.
State Route: AZ 85
County route: MC 85 in Maricopa county

[SignGeek101]

I've never driven in the US (the last time I was there I was 15), but I can share types of roads I've driven up here.

First real road I ever driven was County Rd 47 in Ottawa-Carleton County.
First Freeway: County Rd 174 (Ottawa-Carleton County)
First Provincial Freeway: ON 417
First Provincial Highway: MB 9

The first time I went to the US was in 2008, I was 12 at the time. Obviously, I didn't drive, but here are the first roads I've ever been on there.

First state route: FL 528
First US route: US 441
First Interstate: I-4
First County road: none

[Quillz]

Interstate: 405, most likely. Don't remember, to be honest. But it would have been the 405, the 5, or the 210.
US Highway: 101. And the first stretch of freeway I ever drove on.
State Highway: 27, most likely. Again, don't remember, but this is the closest state highway to my house and it's the most likely.

[noelbotevera]

I do remember some highways we drove, but sometimes it's fuzzy.

Interstate: 95, it was close to my apartment where I lived.
US Highway: 52, for the BBQ fest in Lexington (I won't count US 301 since it multiplexes with I-95 - technically US 301 is the first US route I "drove")
State Route: Not sure, but I think NC 72.
County Road: CR 651 in NJ - really this was a failed fuel stop (no gas at the exit/the gas station was not 24 hours/the gas station was closed down).

[US 41]

Interstate: I-70 (from IN 46 to US 41)
US Highway: US 41
State Highway: IN 163
Provincial Highway: ON 17

Ironically the second time I had ever driven on an interstate was on I-25 between Springer, NM, and NM Rte. 58 in a rental car that I wasn't actually supposed to be driving (I was 16 at the time). Yes I drove from Clayton, NM, to Eagle Nest, NM, in a rental car at age 16. I also drove from Meridian, MS, to Corinth, MS, on US 45 which I also think is illegal since I was on a learner's permit. I think learner's permits are only good in your home state.

[slorydn1]

Interstate (2di or 3di): I-290 (IL) near Schaumburg


US Route (2dus or 3dus): US-45 (Mannheim Rd) near Rosemont


State/Provincial Route: I want to say the Schaumburg office for the DMV is on Golf Rd in the Woodfield Commons Shopping Center  so IL-58


County Route: No Clue, I cannot remember.

[peterj920]

Interstate: I-43
US Highway: US 10
State Highway: Wis 32/57
County Highway: County PP in Calumet County, WI

[Big John]

Interstate: I-43
US Highway: US 41
State Highway: WI 54
County Highway: County EB

[TheHighwayMan3561]

Interstate - I-94
US Route - US 10
State Highway - IL 43?
County Route - Sherburne County Road 32 (MN)

[GaryV]

Interstate - I-96
State - M-11
(both of these were in driver's ed - we got off the freeway at 28th Street, pulled into a lot, and switched drivers)
US - probably US-131.  If BR's count, then BR-131 (Division Ave., again in driver's ed.) 
County - who knows?  MI's counties are haphazard in posting county routes; some good, others poor; others don't even have a route number system, just road names.  I know for sure I was on posted St Joseph County roads back when I was dating the girl who became my wife - she lived on one.  But I may have been on other county routes before that.

[kj3400]

Interstate: I-195
US Route: US 40
State Route: MD 2
County Route: Maryland doesn't have any, so...

[1995hoo]

Interstate: I-495 (Capital Beltway)

US Route: Don't remember for certain, but most likely US-50 (Constitution Avenue in DC the same day as driving on I-495 for the first time....I seem to recall all that was with my dad within a week of getting my learner's permit). If it wasn't US-50, it'd be US-29.

State route: VA-236 (easy one–back when I had a learner's permit, you could neither exit nor enter my parents' neighborhood without using 236, and it is also the state route next to my high school where my father took me to start learning in the car park)

County route: Since we don't have those in Virginia, I don't know. Likely something in New Jersey, but maybe Alabama (if they have them) or Florida. But I have no idea what route.

[Zeffy]

Interstate: I-95 (Trenton)
US: US 206
State Highway: NJ 31
County Route: CR 514

[dfilpus]

Interstate: I-75
US: US 23
State: M-32
County: Montmorency 612

[PHLBOS]

Interstate, US & SR all in MA:

I-95 from Danvers to Newburyport
US 1 from Topsfield to Danvers
MA 114 in Marblehead (my family's house is located along such)
______________________________________

County Route 541 between I-295 & NJ Turnpike (almost a decade later from the above-three)

[akotchi]

I will try to remember . . . it has been awhile.

Interstate:  I-695 (Baltimore, MD)
U.S. Route:  U.S. 50 (Annapolis area, prior to designation as I-595)
State Route:  Md. 665 (Forest Dr., Annapolis area)
County Route:  (Mercer, NJ) C.R. 619 -- Kuser Road . . . back when I-295 ended there.