Welcome to the ODK forum, @arthur2! We're glad you're here. When you get a chance, please introduce yourself on this forum thread. I'd also encourage you to add a picture as your avatar because it helps build community!
Could you be logging in with the wrong account? Google may have changed the terms of their free level for AppEngine. I think you will need to find a way to access your account and increase your plan. Hopefully Google support can help you access your account with them. Unfortunately, we don't have the information or access to support on that.
Please note that Aggregate has reached end-of-life and is no longer being updated or supported. Consider switching to Central because it's actively developed.