The UA sidekicks? Sounds good.
No, the retainers from the strongholds book.
There are three types of followers, Units, Retainers and Artisans. Retainers are a lot like the sidekicks, but much simpler, and are useful without a stronghold. Units are for attacking or defending strongholds, artisans affect costs, etc of your stronghold so neither are any use until after you get one.
Technically I think you are supposed to have a stronghold first, but since you only get that at the very end of the adventure I might give you one each to try out the mechanics.