Assume everyone is HIV positive. Remember you can have sex with HIV pos people and not get infected.
(1) don´t brush your teeth just before sex... do it several hours before and then use mouthwash for fresh breath. Brushing creates micro tears in the gums
(2) NEVER NEVER NEVER NEVER have anal sex as a top or a bottom without a condom. NEVER make exceptions. NEVER. NEVER. Get it?
(3) Be aware that the HIV virus is also found in anal mucus, so don´t finger someone and then lick your fingers.
(4) you are much more likely to die in a car crash than get HIV from oral sex. Do you drive?
(5) be very careful if you have open wounds, cuts etc. Cover them or don´t do any thing where blood, semen or anal mucus is likely to be involved.
(6) For extra safety, avoid cumming inside someone or have them cum inside you, even with a condom.
HIV is not the only STI.
Genital warts are much more likely than HIV. Only genital to genital contact transfers them: you cannot get them on your hands or in your mouth. Before you play with another guy´s ass or cock look at it. If it looks diseased it probably is.
Get tested for all the biggies every 6 months. Get immunized for Hep A and B.
Learn about this stuff: go to your health care provider, talk to the counsellors, get the tests and shots. Keep your anxieties in proportion. Life lived without calculated risk is a living death.
Also, from the look of your profile, you can come and practice with me