You can find your account ID or wallet address in Surf. There are several options to get it:
Press Settings button in the top left corner on the Surf main page → Safety protection → Address and keys.
You can also get the wallet address by pushing Receive button on the main Surf page or via Share address button in the Chain Rider bot.
Free TON address is your address in standard hex format. Alternative address format in base64url is also available so you can interact with the same account through other wallet apps where this format may be used.
When the address is displayed, tap it to copy it to the clipboard.
You can also use Free TON Blockchain scanner at ton.live to get the information about account addresses.