I think I messed up I just need some clarification and help if it’s possible to fix. I sent an alt coin called Audio from my Coinbase to my MetaMask wallet, nothing has been received andI have looked up the transaction that says it was successful. What I did not do was swap the alt coin for ETH before transferring, was this a mistake or is it possible to send Alt coins as they are?
ERC20 tokens have a contract address that wallets can refer to check their balance transfer tokens, and other functions provided by the contract. MetaMask can automatically communicate to contract addresses of popular tokens like DAI which has the address of 0x6b175474e89094c44da98b954eedeac495271d0f. However, there are thousands of tokens that are in circulation and wallets can't keep track of them all. So the user needs to add the token address manually in order for the wallet to communicate with the contract. You should also check the transaction using the transaction id provided by Coinbase on a block explorer like etherscan. Look at the Tokens Transfered section, and you will find the address of the contract and the amount transferred.
To add a token to MetaMask read this article: https://metamask.zendesk.com/hc/en-us/articles/360015489031