Let's add some funds to your cryptowallet so you could buy desirable NFTs.
The amount you wish to add to your wallet is completely up to you and ultimately depends on your goals and how much you intend to use.
Basically you don't need anything but your Metamask wallet to buy and swap crypto. However, you can use crypto exchanges (for example, Coinbase or Binance) to buy and swap any currency or combine these ways (buy via crypto exchanges and swap via Metamask). It's all up to you; in this article we'll run through the easiest way.
Launch Metamask browser extension and you'll see "buy" and "swap" features on the main screen:
Buy - click this button to proceed to the list of trustworthy platforms where you can purchase the most popular crypto currencies. Different networks and payment methods are available, though your options will depend on your region. Choose a platform which features currencies and payment methods suitable for you. After the purchase you will see these funds appear in your Metamask wallet. New tokens are usually added automatically in the list of existing funds.
Swap - This feature enables you to trade your existing funds for a wide range of tokens directly in-app. Swapping via Metamask is an easy way to get specific gaming tokens in case you have a decent amount of the same network's native currency. For example, you need GHST token to play Aavegotchi, which is based on Polygon. Given you have some MATIC (which a native currency for the Polygon network) in your Metamask wallet you can swap MATIC for GHST directly in-app.
Please mind that you will face gas fees for each transaction when buying, transferring and swapping currencies. If you are not familiar with the term, check this article.