I'm not sure if git comes with make, but you may just want to search for make in the folders that contain git.
About mingwpy, I forgot that you're not using python 3.5+, mingwpy doesn't support python 3.5+ so it's not there. I guess you do have to use msys2 for your setup.
However... you don't really need make. It's just that make is convenient if you have it. Instead, just look at the makefile and execute the instructions that e.g. make would normally do for your command. E.g. if you call just `make` to compile kivy. When you look at what make would do in this case (see the makefile), it calls `python setup.py build_ext --inplace`. So, just run this command and kivy will be compiled - no need for make :)
We should have a link to msys2 saying that it is an option, but I don't think we should go into too many details as we don't want to have to support people installing msys2, with *how* to use msys2.