Uh, yeah. There is quite a lot of hooking up going on - but it depends on the hostel! If you want no part of that, don’t worry - there will be plenty of people distracted by plenty of other people. Sex in hostels is, in part, some kind of rite of passage for young backpackers. Just be mindful of who’s around you if you do get down and dirty. A dorm room is a shared space!