hi,
you can try the market section of this forum. also, going to an auction is a great place to learn about what sells, what doesn't etc.
we also have a thread about in world markets which rent spaces here on the forum too!
good luck and welcome!! we hope you enjoy your cats!
*btw, perhaps talk to some sellers or auctioneers on what they suggest. many sell just for a hobby (not expecting to sell) and some sell running it like a real business! some just have fun and give away kittens! whatever you choose, have FUN!