soo many possibilities man!
you could
create music (music is absolutley amazing in dreams, you hear things you've never heard before).
try to enter into a two-dimensional world and be a flatlander.
(im giving myself ideas as i write)
try enetering a 0-dimentional world, where you are nothing but everything.
scubadive.
become a star (an actual one in space). or a banana!
Take away your sight and rely only on sound.
Make multiple clones of yourself.
Go into a a closet/box/washing machine and go to somewhere unknown.
Soooo many possibilities. hopefully these ideas will inspire many of your own.