When Luz Herrera opened her solo practice in Compton, Calif., she had no idea how to bill or create a retainer agreement, what to charge clients for consultation, where to drum up business — or whom to ask for help.

“It took me two years before I felt comfortable running my practice,” said the Harvard Law School graduate. “It shouldn’t take that long, and I don’t think it does for people who have support from their law schools.”