DMV tests and DOT physical before joining a school ??

It doesn't really matter except maybe to the school. You can study for all of the endorsement tests, and all of them are cheap and easy. The HazMat is more difficult and a lot more expensive but all the rest are $10-15 each and pretty easy if you study. Some schools require you get your Commercial Learner's Permit (CLP) before starting class, and some schools you do it the first week of class. It's a bit like organizing your desk before you start school. It will help you to have already passed the endorsement tests. You MUST pass General Knowledge, Combination, and Air-Brakes to get a CDL. You should go ahead and study & pass the doubles/Triples (1 test), Tanker endorsement. BOTH are pretty easy. Tanker is necessary for a lot of freight, not just the shiny round trailers full of liquids. You should get them. You can also study & pass test for HazMat but it takes multiple visits to driver license office (DMV) and it a total of maybe $120 between the fingerprints ($86) and the state fee. You can add HazMat later. If I had the money available, I would also get HazMat when you get the other endorsements just so you have everything going for you.

I use and recommend TruckerCountry.com. They have 10 versions of every endorsement test. The link below will explain how you can study and pass those tests the easy way. I learned it in another industry and it works for any type of multiple choice tests.

Every new CDL driver needs Tanker endorsement.

Passing your CLP/CDL Endorsement Tests - HowTo

 

You can do them all except maybe the hazmat test. My state required me to pass the background check before taking that one.

 

It was good to get the DOT Physical- a lot of states won't issue the permit if your don't have the DOT Med card even if you passed the testing. In Pa they will issue the permit but mark you exempt since you did not turn in a med card.