After logging in, you can see a list of your Projects in the 'My Account' area or by selecting a Project from the drop-down menu! One you've spotted the Project you are looking for, access it by clicking on the Project's title.

If you're looking for a Project and its not visible, there is a good chance your Project Administrator or Organisation Administrator hasn't assigned you to that Project yet. Check in with them first to make sure your assigned to the Project's you require access to!