Make a list of some sort… try to write down as manny things that you are interested in. And do not hesitate to put down even the most mondain stuff. That should give you a pretty good idea about where to begin looking for activities that might interest you.
Another way is to just let yourself be inspired by the world around you. The internet is full of everything… no really anything is on here. Browse your way through the world. A good way to just search for ideas is this…
Believe me… there is a tone of things out there that you will find interesting… just start looking and dont wait for others to take away all the fun that discovering something new brings.
I hope this helps!