I think it's not infrequent that the remit of things turn out to be broader than you expected.
I'd welcome the opportunity to learn - if they're asking you to do this then in a way they're expressing confidence in your abilities.
And, in the situation you describe, all the more reason to ask for some help without feeling in any way embarrassed. Nobody knows everything, whatever they might like to think... Asking for help is not a sign of weakness. I've been working in IT for, oooh, 18 years now, still an awful lot of things I don't know.
Assuming that there is someone in the company that's responsible for server builds etc, find them, and ask for a bit of their time.