When you sign in, by default, you are taken to your personal account. In order to view your company projects, you will need to Swap Accounts.
If you still don't see the projects you're looking for, it might be because the account owner added you as a team member, but hasnt added you to a project yet. Ask your account owner to assign you to a project.
Note: Team members only have access to the projects they've been added to.
Now that you understand teammate permissions, explore more ways to manage your projects: