There was a problem completing your upload. Please verify your email address before uploading a file. Hi everyone trying to upload my first game  but it keeps giving me this error please let me know what to do.

Have you checked your e-mails for a verification mail from itch.io? You have to use the link in the e-mail to verify your account and get access to all features of the website.

If you didn't receive such an e-mail, you can click the down-arrow next to your profile picture (top right) and select 'Settings'. On that page, choose 'E-mail adresses' and you should see a box next to your e-mail adress where you can re-send the verification e-mail. That box will change to 'Verified' once your account has been verified.