Need help in creating a web app [on hold]

I am here for asking which framework to use to build a web app with which will act as a centralized school management web app. It will house more than millions of students, teachers, parents, staffs etc. I am concerned with Language to use, what web server to use, which database to use, would load balancing be required, etc. Can someone help me out? Oh about me, I am familiar with PHP and its Frameworks, Node.js, Python as language, Nginx in web server, MariaDB/MySQL as database server, worked on Redis and Varnish Caching servers. Also which CLoud services would be alright. I have used Google Cloud and Amazon, though I found Google easy to use.