Gay sex and STDs (a bit explicit)

Well, I feel a little scared for all the info in the internet and the taboos around men who have sex with men. I just had a hookup with a random Grindr guy. We blowed each other and he fingered my ass deep. He also gave me a black kiss. I wanna know if I'm in danger of having been infected with any STD. Also, i would love if you can refer me to some sources where i can find scientific and backed knowledge on the topic. I'm just a noob in sex and I'm exploring. Also, I feel a little of itch in my anus. I don't know if this is normal (I think I'm realizing I'm a top haha). Thanks so much.