I have already signed up for the learn & earn program in coinbase, so I'm waiting...
In binance I already have an account, so I'm also waiting...
With Kucoin I'm having a problem: I signed up a while ago. Now I tried to sign in, and it's telling me the email or password is "incorrect". I tried to reset the password using my cellphone, and it won't happen. So then I tried to open another account using my cellphone, and it tells me "the cellphone is associated with another account"...
So let's say kucoin is "on hold" for now...
Just contact the support and avoid creating another account. That's against their rules and you could end up losing access to your funds in both accounts if you do.
If you're unsure about the rates, just go through some similar offers online, or here on the forums (services board). As for the experience, then I would personally try and help translate some big projects like Electrum, zap wallet, Trezor, Bitcoin core, etc. They all tend to have a repository in either Transifex or Crowdin.