How to invest
If you prefer the maximum liquidity approach you can just sign up on a crypto exchange like Binance or Coinbase and buy the coins, there. You can decide if you want to do a market (market price) or a limit (you set the buying price) order.
However, when it comes to investing in Non-Fungible Tokens there are a few more aspects that need to be considered. As of now, the majority of NFTs is tradeable on the OpenSea marketplace which is a decentralized platform and the spotlight of all NFT trading. You must use a Web3 wallet like Metamask to be able to buy and sell NFTs there.
If you do not want to use such a crypto wallet and rather buy NFTs directly with your credit card you can use the Tokapi marketplace which will launch in October 2021. Tokapi will start on the Ethereum and soon will implement the Polygon chain as well as the Binance Smart Chain and whitelist legit projects.
When it comes to buying and selling NFTs you should always have an eye on the floor price as well as recent sales of a project to understand how the market values the specific NFT at the moment. Please note that even within one project there are different floor prices of different rarities.
Always do your own research when investing in anything!