Hi dexm,
I don't have an exact tutorial. How familiar are you with AEM Client libraries? There are a couple of approaches.
The simplest is to create a new client library and add the distributed Bootstrap CSS/JS and integrate that into your page. Part 3 of the WKND tutorial [0] should give you a decent understanding of how client libraries work and can be integrated into your page. The AEM We.Retail sample site actually uses bootstrap (although its an older version using LESS)
If you want to integrate Bootstrap and extend it using Sass it is possible to integrate it into the build process of your project. A similar approach is used by AEM's SPA editor..instead of React you would just be integrating an external Bootstrap project. This will be much more complicated and require some understanding of Maven and AEM project archetype. [2]
Lastly, you may want to align Bootstrap breakpoints with AEM's responsive grid. This is a decent blog post [3] and I believe the author is working on a more technical example...
HTH!
[0] - 3 - Client-Side Libraries
[1] - aem-sample-we-retail/ui.apps/src/main/content/jcr_root/apps/weretail/clientlibs/vendor/bootstrap at ...
[2] - Adobe Experience Manager Help | Getting Started with React and AEM SPA Editor - Chapter 0
[3] - https://medium.com/adobetech/understanding-how-to-use-the-aem-grid-c52fb6ea6efb
