Need help building a stone countertop web app from scratch

Project Broad Description
I’m looking for a long term coach/mentor to help developing a web-based app (CRM) to be used by stone countertop fabricators or manufacturers. This app will need to broadly allow account users to perform several tasks, including:
• Register to use certain functions for free
• Upgrade their account to paying account
• Manage (add/update/delete/email)their customers
• Schedule jobs and site visits
• Create/edit/save countertop 2D drawings similar to:
o Moraware CounterGo: https://www.youtube.com/watch?v=e6rltEs1AQY
o Easy Stone Shop: https://www.youtube.com/watch?v=j-ZgVfYJTCI
• Create and email price quotes and job invoice to user’s customers

End Products/Software Packages
Two possible versions of app: Stand-alone on-premise installation and shared web application

Account and Users
Each stone countertop fabricator business has 1 account. Each account has 1 or multiple users with different privileges.

Please do not send automated response but with answers to the following questions:

Technolo1. gies , including programming languages/libraries you would recommend to use to build this app. Please be as detailed as possible
2. What programming languages/libraries would you recommend for developing the drawing capabilities?
3. Coaching session price/rate/length/format
Deliverables
Answer to questions + a zoom consultation session