A beginner digital camera

Trying to pick my first one.

Up to 500 USD, I guess?

New/used.

Something like Canon 6D Mark 1 (the only camera I consider right now).

For portraits, landscapes, pets, astrophotography, macro.

Digital, decent auto focus, full frame (don't know about this one), maybe a lot of burst shots. Good in a dimly lit room. Don't plan to use additional equipment (lenses or whatever). WiFi, Bluetooth, relevantly easy to transfer photos to PC.

Portable, around 1kg.