WordPress plugin customization

I bought a plugin for a school management The School Management is a WordPress plugin to manage multiple schools and their entities such as classes, sections, students, exams, ID cards, admit cards, teachers, staff, fees, invoices, income, expense, noticeboard, study materials and much more. I bought this plugin from [login to view URL] My website is [login to view URL] I'm looking for the following changes: 1- Registration page, admission, and Student information pages to have the same info on the following link [login to view URL] in addition to that I want to add the feature of the student login, and parent login, Also if the the student is over 18 years old, then he/she doesn't need parents info, nor parent login. Also Stripe needs to be connected on these pages to capture and process credit card information as well. 2- subject needs to be changed from drop down menu to selection instead. 3- I need help to set up the SMS service, which is already built in this plugin, also instead of SMS template, I need to be able to create my own message, and I would be able to send it to one student parent, a single class group, or bulk SMS to all of my groups parents. 4- Same thing needs to be done with Emails as well. 5- Both SMS and Emails need to be moved from under SM School settings to be under SM School (under tab called Communication). Note: there is Database involved in this project (when the forms are changed, the tables on the database needs to be updated as well)