"YouTube University" for Jazz: (Youtube channels and resources that I think are very helpful)
(TONS of videos about literally almost every question you might have about playing in combos and different styles of combos, big band and playing different roles in the big band such as lead trumpet or lead alto, and also tons of videos to help each specific instrument and how to do specific things on each instrument)
(SUPER helpful for rhythm section instruments and understanding music theory in general, especially with how it applies to jazz and improvisation)
(Specifically Live From Emmet's Place has taken off as taken off recently as sort of a "modern-day rent party", and it began mostly during and around the time of the pandemic for jazz artists to play when there were no gigs. However, Emmet's Place has become SUPER popular lately in the jazz community, and this is a great place to listen to what modern jazz music basically sounds like, listen to some of the best modern day jazz musicians, and to hear what great jazz combos sound like.)
(Also any other Learn Jazz Standard backing tracks or other videos from their channel are great)