Customer referral system for in-progress website

We are in the process of rolling out a new [login to view URL] that allows our customers to make appointments online by means of personal accounts. This is completed by making API calls to Google Calendar, where our technician's calendars are hosted. We would like to create a "Referral Program" for our customers, in which they can send their friends/family a unique link to create an account with us. After the completion of the referred person's appointment, the original member will receive a 'token' which can be used as credit for their future appointments. The required work will be as follows: 1. Generate a unique link for each customer that creates an account with our site. 2. Create a system by which technicians can mark an appointment as 'completed' if this person is a referred customer. (More details will be provided.) 3. Incorporate this functionality into our appointment creation process, so a customer can choose to use a 'token' when booking their appointment. We already have an account creation process in place, which uses a MySQL database to store the account information. The work outlined here simply needs to be added. You will be provided access to all existing code to allow for any necessary incorporation. Please inquire with more specific questions. I am a programmer, (and understand the terminology), but have very little experience with web development. You will definitely need the skills listed in this post to complete the project.