First, make sure you have an account registered. By registered you should have gone through the registration process and received an email to confirm your account. That goes to the email you registered with. If it's not in your inbox, check your spam.
Second, once your account has been registered, make sure you are logged in and you can post here in this New User Introduction forum with your username, what GR software you use or wish to learn more about, and what your interest in weather is. If it prompts for a username, enter the one you used to register, not something else. See the attached image to show what is absolutely required as highlighted.
If you can't find your registered account, or you can't find the post you made, it means these instructions were not followed. You have a minimum of 3-4 days to follow the instructions to activate your account before it's deleted.
Required Fields to fill out: