Head to Google.co.uk (The Chrome browser is best)
Top right of the window you will see a "sign in" option, or a Letter in a coloured circle.
Click this letter and you'll see a window that shows which account you are logged in as.
To ensure you have access to things like Forms and Google Drive documents., make sure you are using your atlantic.academy account and not a personal gmail account.
If your account is managed by Atlantic Academy, you are using the correct account.
If the account in use is a personal gmail account, you can add another account and login with your Atlantic Academy email address. the password is the same as your computer login.
Once you have added another account, you can swap between accounts from the list of previously added accounts.