actually we cant say this airdrop is legit or not until it received to our wallet. but please do not give your private key to the form. if they asking the private key of the wallet definitely it will be scam one.
Honestly it is hard to know if the airdrop is legit and helpful, as I can see there are many airdrop in this forum and most of them are fake or a scam.
Yes be careful on what the information you give because maybe you can be hacked.
The only way to know if airdrop is legit when you see that there's no report about it. And also you can know if airdrop is legit when you see that there is an approval from the highest rank.