Books selling portal: B2C portal on Node JS , React JS

Most parts of our website on PhP. https://ssccglpinnacle.com/
we want to change technology from PhP- SQL to MERN (MongoDB, Express, React, Node).
We do 4 businesses on website:
1. selling printed books
2. Selling ebooks
3. Selling online courses
4. Selling Test series - mock tests for competitive exams

Part 4 i.e. selling test series is already on react js

We want to upgrade/ change the website/web portal in MERN technology