You can't transfer or swap the USDT minus having some few TRX in your account. You need to deposit a few TRX in the address, may worth $2 for you to be able to transfer out the USDT
Perhaps you could share the address which you are using here if you don't mind, and we see if it was activated with enough resources.
TSTSpiBhbiSG7bSjnXS6Lw64YsQZ5mDtsn
i dont know why need trx depostit, this s.cks..
In order to use Tron your account need to be activated[1]. When you are making a transaction, you also need fees[2] in order to do it. It is stated clearly on OP, that your account is not activated. That is the thing you should do first, to activate the account.
Send some TRX into the account to activate it and in order to get Energy, which is required as a fee, make sure the deposit you will send is enough that you are able to stake TRX in order to gain Energy. A thorough explanation is available of the two referred links. It does not suck, it's just how it works. If you still think it sucks, simply choose another coin.
[1]
https://developers.tron.network/docs/account#account-activation[2]
https://developers.tron.network/docs/resource-model