Hi Goldielocks,
On the CRA "home" tab after you log in, look at the lower left of the screen. You should see a light blue square with "My Service Canada Account". Click on the "Access Now" link, which is SSO so you don't need to log in again.
Next you'll get a consent page - after you click "I agree", you'll be in Service Canada.
On that page, under the set of tabs that are lower down on the page, click on "Canada Pension Plan (CPP) / Old Age Security (OAS)" and you'll get a dropdown menu. You should be able to find what you're looking for there: contributions, estimated benefits, etc.