Step 1: download or obtain an ER20 wallet such as trust or my etherwallet so you can have a valid ETH address to use to receive your tokens
Step 2: sign up for telegram, twitter and few other social sites. Many airdrops require you to join in their profiles and groups.
Step 3: look out for a solid airdrop to join in and follow the procedures required. You can join in as many as you want but remember there are many scams out there. Never give your private key or personal information to anyone.
So true.