What Jobs can an 18 yr old CDL A holder do?

Anything in your state, a class A has no restrictions with the correct endorsments. Just location restrictions. Intra state. In state only till 21

 

Take my advice and get rid of the chew. It will kill you and it's a disgusting habit.

 

Switch to betel nut. Google: betel nut beauties
It's good stuff & can buy it on Ebay.

Some household goods movers hire drivers under 21 as driver helpers. Cowan Systems hired a whole CDL school graduation class one time in the Detroit area.
Most household goods companies want drivers 23 yrs. old, but some do use drivers under 21 anyway for intrastate.

Cowan has lease/purchase! Don't do that though.

 

Your best bet is to talk to the aggregate outfits in your area, for the answer to this question. It might depend on what their insurance insists on. These construction outfits can be a very good way to get into a career. You mention asphalt, but you will likely get a much wider experience than just that. You might learn to operate various types of equipment, from a "Mexican Backhoe," (shovel,) to actual medium to heavy equipment.
Good luck to you!

 

Don't get your hopes up with ag haulers. I've yet to work for one who didn't expect experience and an age requirement. Not saying don't try, but don't put all of your eggs in that basket.
You can basically do anything intrastate - so long as their insurance provider will cover you. And that's what gets to be the MF.
Basically, apply for anything which speaks to you. The worst they can tell you is no, and perhaps they'll be able to find something related for you to do, in order to groom you for a driving position once you meet their age requirements. Apply for asphalt work at 18, you'd probably be put on a crew. Which in an of itself isn't so bad, except that it's very seasonal work (especially in a northern state). Concrete and dirt crews can continue working a little longer after asphalt crews, but eventually they'll get to that time of season, as well.
While I'm doubtful an ag company would put you right behind the wheel, I wouldn't rule them out... even if they don't put you in a Class 8 truck straight off, you could have a shot at learning to run a loader (added bragging rite in that your job skills won't be limited to driving a truck, to boot), and sometimes they might have you take a single axle out to do small deliveries.
I'd suggest the circus, but they go interstate. That's me projecting though... there's a part of me that's always wanted to run away and join the circus. Asked the other half to join me... told her I'd sell cotton candy and she could be a lion tamer..... got the silent treatment for a while after that one.
If you have the means to go to a trade school, perhaps being a HD diesel tech speaks to you. Now, most private companies with their facilities on private property will have a couple mechanics with CDLs to do road tests, but generally don't require it of most, and so they won't do anything to help you get a CDL. Municipal jobs, on the other hand, will require one. Whether you go in as an EO (Equipment Operator), mechanic, etc.... now, you do have to be careful which division you go with, though... Streets typically requires a CDL, though they might start you off with a requirement to get a Class B within six months, then progress the requirement to a Class A as you move up to EO3 or SEO (or whatever your city/county/state's equivalent would be). Our shop (I work for the Fleet Management Division of City and County of Denver Public Works) requires all mechanics to have a Class A, as all of our property is still public property, in spite of being access restricted. And they help you get a CDL.
So, just a few things to consider. You don't have to go OTR to drive a truck.

 

You can legally drive intrastate in Michigan. However getting that job will be difficult I imagine. What I recommend you do is try to get on in a non driving job. Drive when you can and show your employer your stuff. Just be advised the largest block will most likely be the insurance company. They may simply not allow you to drive. I know several guys that started out as teens working in docks then moving into driving switching trailers and going over the road when they turned 21. Look around you might get a job like this that will help you later. Scour the job ads don't limit your prospects. You might not get that driving job right now, but your attitude during the 36 months between your 18th birthday and your 21st one can help you, or hurt you.

 

You could drive a straight truck or dump. Check with companies that do local deliveries, such as furniture stores. The main problem younger people have is getting the insurance companies to cover you. I think many companies would hire drivers under 21 if they could insure them. The ATA and a few of the larger carriers are trying to push for the feds to lower the driving age for interstate drivers from 21 to 18.