Find a religion/invent your own
If you're not a religion kind of person, try falling in love with someone
If you haven't fallen in love with anyone/think it causes too much misery, find a passion
If you're not passionate about anything, try expressing yourself with art.
If all else fails
You could kill yourself, just to see what happens next.
(This is an unwise thing to do, especially if you have no idea what's going to happen after death)