Yes, it's published in Word because it displays more sharply than a PDF. It is shared from my MS OneDrive folder. You can look but not edit. I can edit to the on-line original if I need to, so it's more accurate for people referring as they get the latest iteration on-line.
OK, well knowing that you have EF-S lenses simplifies matters, so you pretty much have to get a crop-sensor body.
The top of the line camera is the R7, but for both financial and technical reasons, I don't think that is the best fit for your purposes or purse. That leaves us with the R10 and R50... For a comparative review of the R10 to the R50 (and R100) see this video:
Canon EOS R10 vs R50 vs R100: Which Camera SHOULD You Buy? (youtube.com)
If you can manage it, I would definitely go for the R10 - it is a much superior camera for wildlife. While it shares many of its features with the R50, one significant difference is the loss of controls on the back of the camera, particularly for locking focus with the AF-ON button. The R50 is also missing the extremely useful joystick, which is used for a myriad of functions. Simply pressing the centre of it will reset your focus point to the centre of frame, for just one example. The R10 has a control dial on the top for changing various values, EV compensation, but the R50 does not. Finally, the R10 has an AF on/off button on the front of the camera, this is missing in the R50, which means you have to go ploughing through the menus to set it on or off.
The default setup of the shutter button to also managing focus and exposure, and is a throwback to the days when cameras had very few controls. There are significant advantages, particularly for wildlife and sports shooters, to isolate those functions, which is where the extra buttons on the back come in.
Exposure Lock: Given that the camera sensor system wants to generate a tonal value of what it meters that is called 18% grey (because tone is not a function of colour), that is problematic if the subject does not have that level of reflectance, which is quite common. For example, a polar bear should look white, while a gorilla should look black, but evaluative will try to make them grey.
So, it is helpful to be able to set the exposure at a point that has a mid-tonal reflectance. The default of evaluative metering averages out a large area of the screen for exposure, thus tending to be challenge in very contrasty scenes.
There are three ways to overcome this:
- Use evaluative metering and use the exposure compensation dial to overcome the default exposure
- Use manual exposure to set the values yourself
- I have always used spot centre metering to avoid this, as location and locking with a single tap is very fast, and it is particularly useful for applications such as animals in shade or vegetation.
One can assign the exposure lock to the * button on the top rear of the body and configure exposure to cover whatever area you want. So, to lock exposure you point at the selected spot and press the * button, to change that, point elsewhere and repeat. It's simple but offers a lot of control.
Focus: Unless configured otherwise, focusing tends to pick up the closest object to the camera, which is often not what is required. These mirrorless cameras offer amazing focusing features, such as face and eye detection and tracking, but they aren't foolproof. Again, it is beneficial to be able to select the critical point (e.g. the animal's eye) precisely to have that locked and tracked, especially if there are distracting features like a herd, horns (like a giraffe) or vegetation that may otherwise fool the focusing system. So, all one has to do is disable the focus function from the shutter button (see the orange menu for custom buttons) and the AF-On button is already set. Finally, select Servo so if you need to you can track moving subjects that are not caught by the face/eye tracking.
This is explained in many videos, but here is one from Canon Oz that is still valid today:
See: Master Back-Button Focus | How to Back-Button Focus on your Canon Camera (youtube.com)
So, how this works is as follows:
Select the exposure point in the centre of the EVF and lock with the * button
Select the focus point in the centre of the EVF and press the AF-ON (tracking will follow if turned on)
Recompose and shoot
It sounds a lot more complicated than it actually is, but it allows one to shoot in extremely challenging situations with precision. With practise it is very fast. For example: the following image of a red panda was taken when it was deep into the foliage of a tree. If I had not used spot focus to lock the eyes (which face detect then followed) it would have been caught by foliage and been totally wrong. Similarly, there was a lot of contrast in the image and the panda itself was in very dim light, relatively speaking. By metering on leaves (which BTW are about 18% grey) the exposure was correct.
Similarly the following photo of a flamingo was taken when the bird was in a tiny pool of light in an otherwise deep, dark environment. Being able to be precise with focus and exposure allowed an accurate image for both exposure and eye focus. 
The orangutan was another example of using spot focus to isolate the closest eye.
You can pick up a Canon Refurbished unit - good as new and may never have been used, but box opened or used for display or demo. Comes with a Canon warranty.
See: Shop Canon Refurbished EOS R10 Body | Canon U.S.A., Inc
For the Advanced User Guide: download the PDF: c006.pdf (start.canon)
Review of camera:
Canon R10 Beginners Guide - How-To Use & Everything Else You Need To Know! (youtube.com)
As Regards the EF Sigma 150-600c.
I have had this lens for some time and shot with it using the R-series FF cameras with 100% no issues. It should work well with the R10, but you may want to not use the highest drive mode of 23fps - 15fps is a better solution as it gives the sensor (which does the focusing on a mirrorless camera) enough time to refocus between each shot.
