Rental Property Budgeting / Taxes

[Edward Encinas]

I am looking to purchase a 2 family home with an FHA loan and living in one unit. By renting out the one unit my monthly cost is ~$600, but I also wish to put aside ~600 per month for vacancies, Repairs, and CapEx. What is the best way to put aside this money safely and in an organized fashion. Is there a way to put this money aside pretax since it will be used for expenses? In general, how should I go about storing this money?