The following is an excerpt from the CoachStart Manual.

Don’t get too hung up on the charging issue for your first twenty clients.  Don’t worry if it doesn’t come smoothly.  The first skill to practice is inviting people to do Exploratory Sessions and getting “yeses” to that invitation.  The second skill to practice is agreeing on a time commitment to their goals and the coaching relationship: i.e., having the sign up for a coaching structure for one to six months.  The third skill to worry about is to comfortably negotiate and charge your fee.

And you don’t have to learn/practice these skills all at once!  Take your time.