You don't need any software to get started. The beginner-friendly ones don't deliver what you need and the more advanced systems (like bildium) will have you spend more time learning the software than anything else. And I am generally a software guy! We use a lot of IT in my other business, but I can't make a good case for fully integrated property management software until you get into 100+ units.

Analysis paralysis is a very easy trap to fall into. And similar, you can spend time to design a logo, print buisness cards, set up a website, creating LLCs - or you can go and buy properties instead.. 

All you really need is a seperate bank account. We use Zillow to avertise, MySmartMove (Transunion) for background checks, Google sheets of course, bookkeeping  is completely outsourced and they use Quickbooks (I died on that hill more than once, best decision ever to outsource), for communication a seperate cell phone and it's mostly text messages, rent collection via my bank (ACH), and maintennace in a spreadsheet (how much maintenance are you planning on doing??) Leases should be State specific (we use Wisconsin Legal Blank for all forms) and mature / well-litigated, meaning court-tested.

There are very little synergies to integrate these systems. Yes, I may have to type a tenants name more than once, but most of our tenants stay 5+ years, so big deal..