Create/modify Wordpress Plugin

I am building a website for a non-profit Golf group. What we are looking for is a plugin that will allow the booking for tournaments. The setup is very specific and needs to work with the Golf Deputy wordpress plugin for scoring, or have another type of scoring setup for future use. The way we want the bookings to work is that a user (anyone booking a spot in any of the tournaments will already have an account on the system) will login and see who is signed up for each spot available in the tournament (please see attached pic to see an example) and they can sign up themselves, or any of the other people that have accounts (only if they have an account, no one else) to any free spot. People should also be able to take only their own name out of it if they need to cancel for any reason... Right now, this is for one vetran based golf club that holds tournaments at a couple of different courses so we need to be able to have the booking work for different tournaments and times... Please include in your bid the basic thoughts on how to make this work so that I know you understand what we need, and also Start your bid with the word GOLF so that I know you read the project description. If you do not do both of these things, your bid will be marked as spam and not considered at all.