Google Todo app tutorials and pick the one you like the syntax the most and you can complete in a couple of hours. There are gazillion of tutorials out there how to build one. I would follow a React based for learning purposes.
For backend:
Try a simple Express backend with Node.js and Firebase as a database. With a todo app, you will never run out of the free tier and migrating between server provider will be very simple.
Google Todo app tutorials and pick the one you like the syntax the most and you can complete in a couple of hours. There are gazillion of tutorials out there how to build one. I would follow a React based for learning purposes.
For backend:
Try a simple Express backend with Node.js and Firebase as a database. With a todo app, you will never run out of the free tier and migrating between server provider will be very simple.
Level it up with a nice UI library:
https://ant.design/