If you don't mind KYC, you can register for Binance, KuCoin, or other CEX exchanges. But if you don't want to do KYC, you can choose DEX, like hodlhold.com, or other options.

You should have a goal before buying Bitcoin, whether for trading or investing because both are different. If you want to trade, you have to be able to determine when you can buy Bitcoin at a low price, sell it at a high price, and repeat this process to get big profits.

If you want to invest, you don't need to do that. Just focus on buying Bitcoin once a week or once a month and do that continuously.

But you should learn about analysis first to determine when to buy and sell. The important thing is that you can be calm when the price goes down and see it as an opportunity to buy Bitcoin again.