How to buy cryptocurrencies visible on dexscreener.com?

https://www.geckoterminal.com/solana/pools/3RYNdrQ4hbFMQgpHPLAzbiws3qWZvmewNyckvqQFjT6T?utm_source=coingecko&utm_medium=referral&utm_campaign=searchresults

Enter this link or generally go to coingecko.com

Enter the name of the crypto, you will go to geckoterminal and there clicking on swap above the chart will redirect you to the dex raydium or something like that.

Coingecko is a reputable, old crypto portal