The best way is to buy Bitcoin first with your local Fiat exchange. If you use USD or EUR you can try Coinbase, Bitstamp, Kraken etc (look for high volume exchanges)....

Then you should transfer your bitcoin to Binance, which is the best crypto x crypto exchange around. It has large volume, no KYC and is somewhat reliable.

Immediatly withdrawal your funds to your personal wallet after buying. Consider buying a hardware wallet if you have more than one thousand dollars invested.