Have you tried any sports? It doesn't matter whether you're good at them to start off or you have no friends that play them. Lots of sports only need one person (you)!
- Archery
- Skiing (or, alternatively, snowboarding)
- Surfing
- Wakeboarding
- Rock climbing
- Scuba Diving (I've always wanted to try this)
- Horse Riding
- Golf
- Orienteering
- Kayaking
That's all I can think of at the moment, while you might be thinking, "I can't do these!", why not grab a friend and try it? A lot of sports are more enjoyable if you have a good friend with you. You might even make some new ones there!
As for some team/2 or more people sports, I love playing tennis, volleyball, and soccer. I'm not the best at these sports, but once I actually start playing them I don't really care.
If you aren't interested in sports, there are plenty of websites dedicated to teaching languages and musical instruments. Trust me, languages do get easier the more you learn about them (
here); it's the same with instruments as well. Although, instruments can expensive, so I would suggest learning a piano or guitar as they can be bought relatively cheaply (
here and
here for piano and
here for guitar). Back to the languages, there are surprisingly a few Nintendo DS games that teach languages.
You could also try writing or reading on wattpad.com. I can't think of any other websites off the top of my head.
This isn't exactly a hobby, but if you're old enough to be allowed out of the house, you could always walk around your city/town/etc. and if something looks interesting join in! This might only work if you live in a big city though.