I'm a HUD-certified housing counselor and I've been providing financial capability education and training for more than nine years.

If all you are doing is leading a budgeting class as a volunteer you don't really have anything to worry about. Don't offer legal advice, don't tell them anything you don't know to be true and if you suggest any type of service be sure to provide them with at least three options. I wouldn't worry too much about investing - keep it small, practical, and rooted in common sense.

There are plenty of free resources out there that you can use as well - CreditSmart, FDIC Money Smart, CFPB, etc.

And good for you! Thank you for sharing your time and expertise with people that need it!