Does he not like the feel of the leash? Get a cheap, light leash ($ store) and let him drag that around the house (while supervising)....he will get used to that.
For walking take some treats(good stuff like tiny pieces of chicken or hotdog), take a squeeky toy....and walk ahead of him and coax him ....clap your hands...and make yourself very interesting.
Praise, praise, praise.
Most puppies will follow, they do not want to be left behind.
Gina