I can recommend a lot of them, they all have things that makes them a bit different from others. It can be fees, chart etc. It all differs in every of them. But if I’m t recommend one I would say you should go for Coinbase. It’s very simple fee newbies, the only problem is that it’s not available for every location… so I think I should take it out (if their full service is unavailable to you). Next can be Binance, it’s quite popular and you will see a lot of people mention it in this forum.