Jacen Syndulla (not Jason, Jaycen or any other variation) is the son of Hera Syndulla and Kanan Jarrus. His parents, along with Ezra Bridger, Sabine Wren and Garazeb "Zeb" Orrelios (seen briefly in #TheMandalorian S3) are the core cast of the #StarWarsRebels animated series.
Order 66 survivor Kanan Jarrus, originally named Caleb Dume, was the apprentice of Depa Billaba. In Rebels, he would go on to train Ezra Bridger and (in lightsaber fighting) Sabine Wren.
The highly stylized "Clone Wars" shorts were released between the two movies, and are no longer considered canon. Both shows are on Disney+, though you may have to dig a bit for the 2D.
"The Clone Wars" is a 3D-animated cartoon about the Clone Wars, the galactic conflict that begins with "Attack of the Clones" and ends in "Revenge of the Sith."
But the first series to deal with this period was the traditionally animated "Clone Wars."
A key planet in #TheMandalorian - where we see the Bounty Hunter Guild and the Mandalorian covert in the first season - is Nevarro, not Navarro. https://t.co/voeOqEfTnj