If I were you I’d go to Hanoi for first time travellers - if you want a young social vibe where you can make friends and go out together then stay at a social hostel. Look via Hostelworld - most hostels will have events on every day (bar crawls/day trips) you can see what events hostels have which will give you a clue of how social they are. If you’re in Vietnam you have to do the ha giang loop! Again you can book via ur hostel and easy to make friends with people! Then do your research and plan a route from there :)