Try switching browsers. The log in page does this sometimes, if your username and password are automatically set for the log in, It can glitch if you're trying to use a different account.
What is the username you're trying to log in to? Try searching it up on the Forum, and if doesn't come up, then the account is non-existent.
If that's the case, I suggest creating the account again, or contact a Staff member.
There isn't any 'wait time' before you can access your account, It should be ready as soon as you create it.