For US, the first choice to easily buy crypto is Kraken. They fully follow US regulations and available in all states except NY and WA. They provide an easy interface to buy crypto for beginners. You can link your US bank account or you could also use your card. They have all the crypto options you mentioned. Another similar option is Binance.us. It might be even better for some card users. There are also coinbase.com and crypto.com but they have limited coins option. Try these four and find what suits you.
The United States have lifted some laws regarding crypto and we've seen how that's going for the citizens and the United States government. They've accepted crypto generally and moving their edge to ensure they achieved quite important features. Kraken is a good crypto exchange, it provides all the necessary features that's mandatory. OP is new to crypto and you and me understand the fact that he can't adapt every possible new features in the market. You recommend an exchange, OP will need guidelines on how to operate this exchange, more like the buying and selling order. OP will needs all the possible help he can get and most importantly, to stay off scammers.