I traveled there as a late-30s/early-40s single person multiple times and would recommend a few spots for hangouts:
1. Topper's - good outdoor bar with alot of fun locals and groups. Great food and handmade rum as well. (sxmtoppers.com)
2. Celine Pub Crawl - a great night out with folks on a catamaran that hits 3-4 spots for food and drink. Both locations are fun. (sailstmaarten.com)
3. Calmos Cafe - nice bar/grill on the French side (lecalmoscafe.com)