Say: it depends on my mood. Sometimes just chillin and reading a nice book, sometimes I like to party, and sometimes I like to do something totally new!
If you are really into ANY of that haha
He may have nothing better to talk about...things always get kind of slow and awkward in conversations when people are first talking. Seriously, just take the question for exactly what it is, an honest question and answer it. You know yourself better than anyone, so don't over think questions like that, seriously, just think for a minute, say something honest and Beeee yourself!