Hello,
I am very much interested in your project with all of your requirements.
I already developed some android applications such as a cinema movies application connected to an online MySQL database using Retrofit 2 (REST API that makes it easy to retrieve and upload JSON) and PHP, where the user can manage categories, movies, notifications and much more.
I also have another simple e-commerce application connected to MySQL but using Volley which is almost the same as Retrofit along with PHP files for the CRUD (Create Read Update Delete) operations, the user can manage manage categories, products, orders...
Now for your request, I am able to develop the same application as stute using Android Studio which is a very powerful tool, MySql and PHP to communicate between the app and the database, there is also firebase but i don't recommend it because when alot of data is inserted into firebase the app will get slow. I can also provide you an admin panel where you can manage different things as your request. And for the design you can provide me with any design and i apply it in the app or if you want i make a suitable design full of material design.
If you want to collaborate with me let’s discuss it in more detail over the chat.
Kind regards,
Roy Hayek