I just received my apple watch but found out the band not suitable for me.. can change?

You are addressing this to another user and not to Apple in this forum.

Apple Support Community Forum

This is Apple Support Community forum, primarily for a user to user interaction for information & idea sharing between users, if need be, extend support on technical know-how in handling Apple products from a more experienced fellow user, This is not the right forum to discuss with Apple Inc.

Please contact the Store from where you made this purchase.