I would recommend full frame mirrorless.
Full frame for easy and cheaper choice of lenses.
And mirrorless for easy integration with new apps etc.
I don’t believe there any advantage in APS-C sensor in a modern world. It rather marketing. Canon was ignoring this format for long time in the mirrorless format.
Keep in mind, camera is a platform, armament is your lenses. Not just buying F16 or A-10C for their look, and then trying to match you favorite bombs just to figure out they are not compatible with your platform 
With canon most affordable and artistic lenses are:
- RF 50mm 1.8 ~$150 used (can’t find cheaper and better) able to focus closer than other brands
- RF 45mm 1.2 $450+tax was just announced and no used one. Incredible wide aperture for $
- RF 85mm IS F/2 macro. ~$500. image stabilization, able to focus close for lips, eyes, smardolls.
This is a modern full frame lenses, that is much better any DSLR, specially APS-C versions
For zooms you can look at either:
RF 28-70 f/2.8 IS wider aperture but shorter zoom range
RF 24-105 f/4 IS smaller aperture, but wide zoom range, weather sealed
Both image stabilized. About $900
Now the platform for RF mount is either:
- R8 below $900 or so used (but check local Offer-Up)
- RP below $600 or so used (but check local Offer-Up)
RP is an older version of R8. And I would buy if budget is absolutely required.
I would avoid Rebel for:
- it is crop. That limit choice to mediocre lens line up. Forces to cost ineffective choices and make life just harder.
- it is not mirrorless. You will miss all new experience and learning curve will be harder.
I like Canon, as they joined mirrorless movement at the last moment. And was able to learn on Sony mistakes. RF is one of largest diameter mount, that simplify some optical solutions. They have either expensive lenses, or very cheap and incredibly efficient lenses. There is a moan that they not allowing 3rd party lenses, that I don’t see need to. The recent 45mm f/1.2 for $450 one more argument to prove it.
You can’t find better than R8 hybrid camera that shoots 40fps stills and 10bit HDRs videos. Not to mention 180fps slow motion etc. for only $800. But that about camera, lens are even better 
To sum up. Cheapest entry is: Canon RP + RF 50mm 1.8. If budget allows, get better lens. Camera can be upgraded later. Lenses are main tools, loosing value very slow, good investment. RF mount is the latest from Canon and unlikely change in many years. EF lenses can be mounted over adapter, but it add cost, weight and newer RF lenses are just better by optical design. I would not look to start from outdated technology.