On the WAX Blockchain, there are 3 different resources (NET, CPU & RAM) to allow you transact and store information on the blockchain. CPU & NET allows you to send/sign a transaction on the blockchain while RAM allows you to store information on the blockchain.
In order to get more of these resources, you will need to stake/lock in WAX tokens on your account (Under the "Resources" tab in your WAX Cloud Wallet). The more WAX you stake in these resources, the more you are able to transact on the blockchain. NET & CPU replenishes every 72 hours; meaning after you have utilised a certain amount of NET/CPU to carry out a transaction, the amount of resources used is automatically replenished 72 hours after that transaction. On the other hand, RAM is used to store information on the blockchain such as your NFTs. RAM can be bought and sold on the open market through your WAX Cloud Wallet.
When you start using the WAX Cloud Wallet, you are given 1 WAX in NET, 1 WAX in CPU and about 5000 bytes in RAM. Most of the time, you'll run out of CPU/RAM rather quickly and you should stake more in them. Roughly 50 WAX in CPU and 5 WAX in NET should allow you to transact within the blockchain for a sufficiently long time!
If you find yourself having excess resources, you can unstake your WAX tokens and the tokens will be returned back to your account in 72 hours. This is also another safety precaution you can take; for example if someone gained access to your account and wishes to take away your resources, you have 72 hours to regain access to your account and protect your staked tokens.