how to access google drive from gmail
On your Android phone or tablet, open the Google Drive app. At the top, tap Search Drive. Choose from the following options: File types: Such as documents, images, or PDFs.
When you send messages in Gmail, you can attach files from Google Drive, such as documents and photos. This is especially helpful if the document is larger than the Gmail file size limit, or if you want to collaborate with others on the document
You can sign up for a Google account using any email address you have. It becomes a unified login across all of Google’s products, such as Google Drive, YouTube, Sites, etc. You can use a Gmail or your company’s existing Google Apps account to act as a unified login across Google, but it’s not required..