Since today you can start mining Bitcoin Gold. Soon you can use CosmoPool for it.
Here is their link
http://cosmopool.online/but what wallet address do u use nobody seems to fkcing answer that question
You can just use your bitcoin address.
Be carrefull : it is just the testnet : the coin haven't any value.
It is just for a few time, just the tie to test your production setup :computer, GPU, Pool, and all your parameters.
Mainnet will be available later, probably next week...