Hello Arindom
There are currently no VXLAN lessons in the Networklessons site, however, as you can see from the new lessons that are coming out below, Rene continually updates content and adds materials.
I suggest you go to the Member Ideas section and post a recommendation to add VXLAN as course content.
In the meantime, if @ReneMolenaar may have something more specific for you to take a look at.
I hope this has been helpful!
Laz