Title says it all I(22MtF) am a month into my first poly relationship and I couldn't be happier not to say everything's perfect its definitely been a weird adjustment but this girl(21f) makes me feel so freaking happy i dont want to stop seeing her.

I'm sharing this amazing girl with a few people but we live the closest so I'm almost always with her, while she just let me know that she's going to get a STI test but just for her normal 3 month check so no real concerns. That being said I don't know much about anything, this is my first sexual relationship and I want to do everything I can to stay healthy not just for her/me but for all her partners too! With all this being said I don't really know how to go about being safe other then using condoms?

Now I did learn about sex safety for about 5 minutes at my catholic high-school but me being Transgender and not knowing, I never saw myself getting in a situation where I'd be with someone so I paid little attention but I'm ready to learn and I don't know where to start even if it's basic how do I stay healthy and what are some things I need to look out for?