The training grounds in the forest are available to be used to teach classes. You can charge whatever fee you want for your classes, it's up to the instructor on what they want to charge. I keep it running with funding from the Government. It was built as a place for the patrol teams and others to train in their downtime, so I've been able to pitch it as a place for teams to keep up their skills and train together if they want.
There's also the Underground. I don't know if they're hiring or not, but they also teach classes.