Windows server in small business

Good morning
where I work, it's a very small company, there are 9 workers, my boss would like to put a server and told me to take care of it. I am an IT expert now close to retirement, and years ago I was a good systems engineer, but now I don't remember almost anything, perhaps he isn't even interested in buying a domain, which we don't have now, so a powerful NAS with the possibility of virtualization. However, can anyone recommend any tutorials or books to help me get up to speed?
Thank you
Fabrizio