It can happen. You signed up with your personal email address rather than the one that you use at work, or at uni.
Perhaps you've tried to create a ride and been rejected, or have received an email to let you know that all is not good with your account.
Don't panic - there's no harm done. Just create a new account with the correct email, and continue on your way.
Your original account is sitting in limbo, in a carpooling network designed specifically for wrong email addresses, and will stay this way until it's eventually cleaned up.
If you're still having trouble with signing in, though, just contact firstname.lastname@example.org and we will get you up and running.