I want to learn - where do I start?

[I hope this belongs here - if not, lmk and I'll delete the post. I've been mainly lurking here so far]

In a month I'll be in charge of "IT-stuff" in a small office. People are generally happy if there is internet and VoIP is working. I'd like to take the opportunity to learn what I can, while I have the chance. And maybe/hopefully contribute to make it a bit better. For now I want to look into how I should configure wifi and access for office/guests (and devices that are used obv.) Thing is, I don't know where to start and what I actually can do. Do I just google "how to configure wifi in the office?" and go from there? (I'm a bit hesitant to do that since I'll not be able to tell if what I find is good) Is there any good reference material you would suggest? Any suggestions are appreciated.

I studied business informatics (but it's been a while) so I'm not completely clueless (but still clueless hehe).