@corey_414 - The base mod alone doesn't do anything actually. It's a loader for the custom diseases that exist in the add-on modules (Minor, Long-Term, Goofy, etc.).
Once you have the base mod plus at least one of the custom disease packages in place, then yes on City Hall, NRaas > Vector > Diseases > Enabled to select the ones you want activated.
If you want to start an outbreak manually instead of waiting for one to start by itself with a randomly selected Patient Zero, then again on City Hall, NRaas > Vector > Outbreaks >Start Outbreak > (select already activated disease).
