There is no need to enroll in a class unless you have no access to a vehicle to practice with or have no one to teach you.
I got my class B w/ air about 3 years ago. Just go to the DMV and get the book and read ...and read ... and re read...... then re re read. Take the computer test and they schedule a road test. The B is easy, mainly the pretrip inspection will be the hardest thing to study for.
Then I went and got my class A a year later. I only had a Freightliner columbia class with a extended sleeper and a 48" spread axle single drop trailer. Basically, its the worst thing i could have used in the road test. But I only ran over 1 cone. (either run over the cone, or drive in the grass since the truck was too big for the parking lot...
)
I don't have a hazmat, but you gotta be retested every 2 or 4 years for that. No tank, but wouldn't mind getting that incase I need it in the future. I don't plan on driving buses so no need for the "passenger" endorsement.
The more endorements you have, the more your license costs to renew.
But the first step is to go to the DMV and get the book and start reading.