What the test is and which of the two live CDL manuals your state is giving, which class of licence the two weight ratings actually require, every endorsement and restriction letter, the learner permit and the entry-level training you must now complete before the skills test, what takes a licence away, and the two hours-of-service clocks that run at different rates.
Score 80% or higher to earn a certificate.
Every legal answer here is federal. Your state adds to it, and a few states test material that is theirs alone — so a right answer here can still be an incomplete answer at your own licensing office.