The first big novel, by Charles Soule, is called Star Wars: The High Republic: Light of the Jedi.
There will be novels and comics set in the High Republic, including stories for teens as well as younger readers.
It’s “set in an era when the Galactic Republic and the Jedi Order are at their zenith, about 200 years before the events of Star Wars: The Phantom Menace.”
Light of the Jedi is already available for pre-order; it goes on sale (along with more of the first wave of High Republic books and comics) in August 2020.