TIKTOK PAID ADVERTISING
It's okay, you made a mistake at $300. In any case, if you are willing to send your money to a random website after a Tik Tok ad, you would have lost your money anyway at some point.
Would you buy a car without getting a driver's license?
Why would you want to buy cyptos or BTC if you don't understand anything about it? If you had done at least 3 Google searches, you would have heard of Coinbase, Binance, Mexc, Coinex, Bisq, Localbitcoin...
There are literally dozens of legits CEX and DEX that can be found in one google search.
So if it ever helps you to accept your losses, know that with so little time invested in your research, there is a 99.99% chance that at one time or another, you will lose your money (address error, network error during a withdrawal, scam of all kinds etc...)
A lesson at 300 usd is expensive but it's still better than a lesson at 3000, I don't mean to sound dismissive but this is just an uninformed beginner's mistake. Now, at least you know. Good luck for your crypto / BTC journey ! Hope that you won't be disappointed next time