Use “who” in clauses where the subject of the pronoun is a person or persons, and “that” for things (including abstractions).
We are looking to hire someone who can manage our social media accounts.
A stronger social media presence is something that we need.
If the subject is a place, use “where” or “that,” whichever makes more sense to your ears.
Our HR director has a private office where she conducts confidential interviews.
Alaska is a place that I’d like to visit someday.