Receive a blow job after condom sex and u cum in someones that might has HIV or might not mouth the only way u could get it is through blood right?

Probably okay. Receiving unprotected oral sex is a very low-risk activity as far as HIV transmission goes. You're young and new to a dangerous world. You can catch gonorrhea or syphilis this way, and in this day and age, your semen is now in the possession of someone you may not know well, which presents a small but real risk of ruining your life.