In terms of not knowing what you want to do, don't worry about that. Most people never know what they want to do as such and just move from thing to thing. I certainly do. Focus on your short term goals instead if you don't have a big plan - like I wanted to live abroad so I made it happen. Don't worry about the big picture of what you should be doing with your life or whatever. It will only make you anxious. Focusing on smaller things like getting fit, making friends, getting a job somewhere decent, etc. etc. will be better for you imo.
Obviously try and improve your useful skills and work in industries that are lucrative or you enjoy, but don't overly pressure yourself if you don't have a career path all figured out at whatever presumably young age you are.
On the friends thing, having hobbies that allow you to meet people is good. Once you're out of school it can be difficult to meet new friends - the key is to just get yourself out there and in situations where you can meet people. Get back in touch with people you used to know too. Could be a little awkward but if you have nothing to lose, so what?