If you're looking to test this site then you'll need to be able to access the site from the perspective of each of the user types.
To do this, you'll need to login using an incognito (anonymous) browser window using one of the following user accounts:
How do i test each user?
Once you're logged in as that user, you need to do your best to think like that user - as if they don't know the rest of the way that the site works. If from that perspective something doesn't make sense then we will need to change the site so that it does.
By logging in to the site as a different user you will have different permissions - so you shouldn't be able to see all the sections of the site - it's important for you to try and be aware of what each user level should and shouldn't be able to see / access so that you can properly test and identify any issues.