I’ll promise not to rant too much about companies who are polluting the UX title with stuff like this…but… I don’t know what the job market is like where you are, but the market here (in the Netherlands) is desperate for all sorts of UX types, it is also always a good place for developers - which is seemingly what you’re being asked to become!
If your company is wanting to change your position, and you are happy to do that, then they should be sending you on the training courses to ensure that you get up to speed too!
I can (and do) code, but I tend to now do it only on my own projects - at my workplace I find that I can get the point across really quickly and easily using Axure when it comes to the prototyping stages. If you have to produce code at the end, then tools like Macaw do not really push out clean usable code, so if you do have to produce code too, then I think hitting the text editor is perhaps the best way forward.
The specifics: GitHub looks intimidating, but it truly isn’t. Download either Github for Mac, or Github for Windows, and then do a search for a tutorial on how to use that app. I’ve found that I don’t actually do any commits directly at Github, but do everything in this app - it is super user friendly, and you’ll pick it up in no time!
I have no experience with Angular, but for SASS, I can totally recommend this book - http://sassandcompass.com/ - If you know CSS then you will be fine - there is also a book out on A Book Apart, but I haven’t gotten around to reading it yet. You’ll find with SCSS that it will improve your code, then you’ll have a ‘aha’ moment, and you’ll realise better ways to do what you want to do. It actually makes CSS more fun.
Hope this helps, but like I alluded to, I hope that you go in the direction that you want to be going in. Good luck!