Blog, Kanban board, Todo list, Chat app, CMS for a blog or something similar with some authentication involved, Social media feed, News app (can probably hook in to an API like hackernews for this). Just a few from the top of my head :)

There are some ideas here you might be able to use: github.com/karan/Projects#web

I have no affiliation with the author.

Everyone Has Faced the Problem that you are facing right now and that is you are not coming up with the idea to practice what you have learned by now. And Believe me unless you will not make a project using the things you have learned you will not face and difficulties and hence will also not grow.

The very simple solution to this problem is that you should look around your surroundings and look for the problems to solve.

I will give my example here, when I was in 5th Semester and We had to make a Project using MSSQL Database, we went to the Mobile Phone Shop of cousin and offered him Mobile Shop Management System and We made him Mobile Shop Management System, at that moment all concepts that we learned till that time came into use, concepts of Software Engineering, Data Structures and Documentation as well.

So that was a very good experience for all of teammates.

The first thing I built in React was a Todo list. There's a reason Todo is so common, and that's because it cements the basics. It's simple, but not too simple. It'll let you get a handle on events, unidirectional data flow, interpolation and basic JSX. Add in some color coding so you can get some practice on working in CSS in React.