These are your virtual wallets which you use to store your tokens. When you apply for airdrops, you will be asked for your wallet address and this is where your tokens will be stored when they are distributed.
There are different wallets for different tokens and projects.
Most projects host their projects on the ethereum blockchain, hence prospective token holders need to have an ethereum wallet address.
To get one, register here.
Or a more easier way is to download the IMTOKEN app.
Some projects host their tokens on the waves blockchain as well.
To get a waves wallet. Register here
Get one here
Get one here
Facebook accounts are basically needed for publicity of airdrop projects. Tasks such as liking pages, sharing pages and posts are always required.
Register here
Twitter accounts are another essential prerequisite. They are used for publicity of projects.
Register here
Register a reddit account here
Get one here
Bitcointalk.org is a very popular cryptocurrency forum. Some airdrops require it's partipants to have a bitcointalk account.
Register on bitcointalk.org
Download the instagram app on Google playstore for Android or Apple Store for IOS.
Or access instagram via web on Instagram web
Register here
Some airdrop projects create videos that explain their projects better and require that participants watch and like their videos and subscribe to their pages as well.
Access YouTube via the app or on YouTube
Get Telegram on Google Play Store or Apple Store.
After installation. Create an account on the app.
Verify your number. Then go to settings and put a username.
This username is what will you will provide when asked for telegram username on airdrop forms.
@ubongj for 
@steemjetdrops
@ungest
@udezee
@enolife@ubongj