Seeking digital camera for new photographer (Horsham, PA)

I am looking to learn photography and would like to find a refurbished camera.
My goal is to see if my talent can lead me into portrait photography.
Budget: I would like to stay in the $200-$300 range (depending on the camera, also open to higher for a great deal) What's important: excellent/good condition low/mediun shutter count camera that will go fully manual and that I can change the lenses on A few that I'm interested in: efs 17-55mm f2.
8 EOS Rabel SL3 Digital SLR Olympus OM-D E-M10 Mark IV Canon EOS 70D Digital SLR Camera Open to other ideas - just familiarizing myself with photography cameras.