You must know what kind of USDT that will be stored in your wallet. USDT has so many kinds of smartcontract and you can check it here. https://coinmarketcap.com/currencies/tether/

If you're wanna storing your USDT erc20 and you can use mycrypto but if it didn't ERC20 asset and it's better try to use the multiple wallet just like trustwallet, token pocket and etc.

Those wallets have been supporting multiple blockchains which already supported by USDT. You must also remember to use only popular wallet because the security can be trusted.