To start with crypto you will need a wallet like Metamask.io - this is a Chrome extension that will allow you to interact with web3 apps and protocols.
There are four types of crypto airdrops:
1. L1 blockchains like Aptos and Sui - Aptos crypto airdrop is finished for now, but Sui is upcoming!
2. L2 blockchains like Arbitrum, that extend existing blockchains (mostly Ethereum)
3. DeFi protocols, that usually give you access to swapping or lending/staking - look at defillama.com or airdrops.io
4. NFT airdrops or NFT free mints that are hard to come by and popular - you usually need to engage with the community to be eligibile for a free mint. Conditions depend on a particular collection.
Crypto Airdrops are the best way to make money in crypto.