As a class A holder myself you do not want to take the physical while you are on pain pills. No no no! That will go on your DAC report and that's something you don't want. Since it sounds like you are getting your permit instead then taking a written test is no problem. In fact use this time to study and get all your endorsements as well. However only take written for hazmat. Again nothing with a urine sample should be taken. Also understand that it will stay in your urine or hair follicles (most reputable companies require both) so the sooner you get off the pills the sooner you can take your physical.
Been driving for a year now and I said once I hit a year I was going to ***** myself out to the highest bidder. Monday I start with a new company where I will make a 6 figure wage. Those companies are out there if your DAC and MVR stay clean. Think long term.
Also if someone asks you for a social media account like FB or Twitter tell them you do not have one. They will examine all your posts. If you have any medical condition and it does not prevent you from passing a physical then don't list it. As an example say you use a cpap machine. Almost all trucking companies will require you to have another sleep study paid out of your pocket before you drive for them. Understand this, you do not drive for a trucking company. You drive for an insurance company because it's the insurance company that determines if you are a risk or not. If the insurance company says you are a risk, for whatever reason, the trucking company will not hire you because the insurance company is going to ask them, why did you hire him? We told you he was a risk. No trucking company is going to go against the insurance company.