If you don't already have these details, you'll need to first retrieve your login information before proceeding with the steps we'll go through shortly. Some email services need you to complete email forwarding before importing your contacts and emails. And, the same is the case with AOL mail login and Gmail.
After you've finished with the email forwarding process, you can move on to the following steps:-
1. First and foremost, open the Gmail application.
2. Go to your Gmail account and sign in.
3. On Gmail's main page, select the "Cog" button to access the "Settings" menu.
4. Select "Accounts and Import" from the drop-down menu.