So my question might be a bit newbish but do you need besides tether in your wallet also ether for paying gas, or in other words you need two?
Yes, as long as the Tether(USDT) is an ERC20 stablecoin, it will require a eth in your wallet to cover for the transaction fees, and it's not just Tether(USDT) this is applicable to all ERC20 tokens, or all tokens running on the Ethereum blockchain, i just hope you are aware of the high cost of transaction fees on the Ethereum blockchain, if you can afford paying $25+ per transaction then you are good, but if you can't its best you stay away from eth and ERC20 tokens from now becuz of the transaction fees.