You can confirm that you are using the testnet contracts by checking your URL and by looking for the "Alfajores" banner next to the wallet connection in the navbar.
Pools / Markets
In Alfajores, right now we only support trading between cUSD and CELO, so there is only one pool: cUSD/CELO.
Mobile users
Celo is mobile-first, and Ubeswap will work with Valora and any other future Celo wallets. The Alfajores deployment of Ubeswap will only work with the development mode version of the Valora app. It will not work with the normal version of Valora that you may have already installed on your phone