The ErrorTrap and OverWatch mods don't show up per-se automatically. You either click on City Hall, or use any computer in-game to get to Nraas options.
For example when you're in Live mode and have an active Sim, click on City Hall to bring up the Nraas options. You should be able to click on your Sim and see an Nraas option as well, depending on what mods from them you have installed.
It's my understanding there is no setup to do for ErrorTrap. It just runs in the background and does it thing.
There are a few things you can setup in Overwatch, depending on your personal preferences.
The site linked below can help with getting to know Nraas Mods and how to set them up.
Sarah Sims - NRaas Settings
https://simsarahsarah.tumblr.com/nraassettings