When using mainstream exchanges like Coinbase you can be rest assured your funds are safe. However, they do have some restrictions and KYC sometimes takes ages. Even with a verified account they will hold your funds for 30 days and your value will drop most likely. whoever suggests coinbase isn't experienced. Thus, i think the easiest and safest way is just to use Binance, which takes Visa and Mastercard, and only 10–30 minutes to get your BTC once purchased.