I had a question regarding starting hrt, what do they look for during the blood test prior to starting? Is a blood test mandatory? If you drink alcohol or smoke weed or do other drugs what are your chances of being rejected if at all?

Blood testing will look at your chemistry and hematology profiles, just like for a standard check-up.  You will want/need to be in good health.  Prior to starting HRT you should discontinue any drug use, including alcohol and tobacco.  You need to disclose to your physician prior and current drug use of any kind.  To do otherwise is risking early death.  Hormones are serious business.