Fray
Appreciate you are a beginner, so forgive me if i give you any advice you already know.
1. Clients are not assigned to secondary sites. Clients are only assigned to Primary Sites.
2. The errors you are seeing sound to me like permissions errors. Check all of the following:
a. Permissions on the System Management container must include the computer account of all Site Server including the Secondary Site Server.
b. Permission on the database for the account you have specified to run your SQL Services. If you have specified"System" the you must add the
computer account even though this isnt good practice, it will get things working.
Hope this helps.
Chris