Need testing advice ASAP

So a family friend of mine invited me and my sister on a vacation. It was really lovely but the friend ended up getting drunk and telling us all about her sex life…

Needless to say she is completely irresponsible what she’s doing. Having unprotected sex with people she just met, sleeping with everyone and anyone (man, woman, and everyone in between…) and is just overall really weird and disgusting when it comes to sexual hygiene and education (on purpose too, it’s not like she doesn’t know).

And now I think she used my towel and some of my other products. I’m terrified of getting any kind of disease and I’m aware that sharing towels and stuff can lead to STDs. What should I test for when I get home? What should I look out for?

(I’m saving myself for marriage and never had any STDs before for reference so I have zero idea what to do.)