As an R6 owner, this is a fantastic camera, particularly for its capability to take photos in very low light and for its amazing autofocus system. I use mine regularly at a nightclub and concert venue and I’ve probably taken 60,000 shots on this camera that I’ve had for not-quite two years. Yes, it’s “only” 20MP, but that still means 300dpi prints on 11x17 (Ledger) paper.
Canon DOES have the substantially less expensive R7 releasing this July, which is $2000 cheaper and has a high MP sensor, with all the same autofocus bells and whistles, at the mild cost of having an APS-C rather than full-frame sensor. This means that every lens attached to that camera will have a 60% longer focal range. That’s great for birders and sports photographers and a real detriment to anyone wanting to take wide angle shots with affordable lenses. Still, $2000 is a LOT of money and the capabilities overall are very close, so it might be a better option for many people looking at this body right now.
This camera uses Canon’s RF lens mount (as does the R7), which doesn’t have tons of affordable lenses. I think the 35mm/1.8 is my favorite of the less expensive options, although there’s nothing wrong with the 50mm/1.8 or the Samyang/Rokinon 85mm. The 24 - 105mm/4 is also a great lens, but it’s an L-series lens and not cheap at all. Getting a Canon EF to RF adapter is definitely a good idea, as that opens the option to Canon’s older lenses on this new mount. The Canon-branded adapter is a little hard to find, but having tried a couple third party options, I’d rather have the real deal for best compatbility.