I've taught friends on an individual basis but did not charge.
Be prepared for some of them to be totally clueless! And for others to think they know a lot more than they really do.
Also you will find that some are more interested in making clothing than quilts and vice versa.
Decide if you want to teach a basic sewing class which could then prepare them for either garment making or quilting OR if you would prefer to teach a class that is dedicated to a particular project - wall hanging, table runner, tote, etc.
Have fun!