So I had some bitcoins at time of the fork. Do I have the other new coins as well? How can I spend, sell or buy them? Is there a multibit for bitcoin cash?
There are some new wallets that support BitcoinCash, but being new, they are not trusted yet. Here's the official procedure to safely use the Electrum Cash (fork) wallet according to the non-fork creators: https://electrum.org/bcc2.txt
Even after you do that, most exchanges are not yet supporting importing BitcoinCash into their accounts. Once everyone is able to do so, the price is expected to tank. I guess we'll see...
The same can be said for everything you own.