Had [m]y first experience and I'm scared

Hello I'm new here and I recently was on the receiving end of sex. There's a lot happening in my head right now... This experience was just 2 days ago.Uhm anyways the main thing I'd like someone to talk to about is I'm scared of STDs. I've never had sex before and I'm just kind of panicked. I met an older guy on Grindr and he was really super nice and seemed healthy and well off financially, but of course anyone can have something like AIDS.I don't really want to contact him and ask for a STD test from him, I feel that would be really weird and kind of rude... Idk what should I do? What are my chances of contracting something?