Where do you buy monero?
Coinbase
See markets here https://coinmarketcap.com/currencies/monero/markets/
Christopher Greene
Kucoin. You can spot trade your USDT for Monero. Then, you move it to a wallet.
Which wallet are you using for monero?
Here is a step by step instruction to use your ledger as a cold storage for Monero.
https://support.ledger.com/hc/en-us/articles/360006352934-Monero-XMR-?docs=true
You won't see your Monero within LedgerLive however, you'll use a third party application.
Here is a video taking you step by step through these instructions.
You have to download a monero app from the ledger. It has it's own wallet through some app downloaded in your computer.