Final answer:
The best first step for Ruby to take based on her accounting knowledge is to budget to figure out how much rent she can afford for her own apartment.
Step-by-step explanation:
The best first step for Ruby to take based on her accounting knowledge would be to budget to figure out how much rent she can afford for her own apartment.
By creating a budget, Ruby can carefully track her expenses and income, and determine how much she can allocate towards rent.
This step is important for her to understand her financial limitations and make informed decisions about her living arrangements.