If you're searching for the tutorial to kick off learning React, you could first check the official docs.
Learn concepts
In case you're a type of person which prefers to learn the concepts before typing any code, head to Learn React which covers basic principles of React, but also dives in advanced topics like managing state, and escaping hatches. You should also see Rules of React to help you write well organized, safe, and composable applications.
We recommend to check the basic principles first and have that settled in before exploring advanced features.
Learn by doing
And for those who prefer learning by typing their own code, visit Tutorial: Tic-Tac-Toe which explores React concepts by building a tic-tac-toe game. This will cover all you need to know in a couple steps:
And for best learning experience, feel free to combine the two approaches and have some fun as well. Don't forget to check out other useful resources to expand your knowledge even further.