Google Account page: https://one.google.com/storage/management
Tutorial - https://www.majorgeeks.com/content/page/free_up_space_gmail_google_photos_google_drive.html
Gmail, Google Photos, and Google Drive offer a reasonable 15GB of free storage. Google also offers Storage Manager to help you find and delete extra, discarded, or large items to help you stay under your 15GB of free space.