Official Microsoft Paint for Mac doesn't exist. But there are in fact more accessible alternatives that allow you to do better things and present much less of a learning curve at the same time. One of them is already installed on your Mac by default, only that its toolkit is hidden inside the app called Preview. Get a Paint replacement with Setapp. Plus, in OS X 10.10 Yosemite, you can use the markup that are part of Preview.app from within Mail.app (as soon as you have the Markup extension enabled (see System Preferences Extensions Actions). Depending on the way you want to create your snapshots (i.e., for instance, including menus and the mouse), you might want to consider Grab.app.
If even Mini vMac is too much for you, there are couple web-based options that get you most of the way there. PCE.js is a browser-based Mac Plus emulator that allows you to play with several old Mac applications, including MacPaint 2.0. This version is somewhat different than the 1.x versions, and you can't save your files, but this is a very cool option if your computer/browser can handle it. Another option is Cloudpaint, which is a re-implementation of MacPaint in JavaScript. It's not totally true to the original and has some quirks, but it should be a little more lightweight than running an entire emulator in the browser.
https://coolfup196.weebly.com/sticky-and-speedy-mac-os.html. Those with no experience with pre-OS X Macs will want to start with the online options or with Mini vMac. Using at least System 7.1 with Basilisk II or Sheepshaver makes sense, and for all intents and purposes this requires a new large HFS-formatted (not HFS+) disk image, which is non-trivial to create these days (see FuseHFS below). Freely available floppy images are more than sufficient for Mini vMac.
https://coolmfil904.weebly.com/there-is-a-planet-b-mac-os.html. If any terms here are unfamiliar to you, start with Mini vMac or PCE.js. They're very easy to use and work well.
NOTE: despite them not being available for sale for over a decade, it is illegal to copy and distribute old Mac ROMs, which are required to run most emulators other than vMac or PCE.js. If you're going to do this, make sure to rationalize it somehow. https://bestbfil552.weebly.com/number-13-movie-trailer.html. Some of the Apple OSes you may want to use are also not freely available from them, so do be careful and ethical online.