It is the easiest software to get help with as you scale, and the easiest to delegate to a professional. 

What I would suggest is signing up for a Pro Membership to BiggerPockets so that you can use both softwares for free. https://www.biggerpockets.com/blog/pro-partners

Software used for maintaining property financials is intuitive and distributions are made timely on a monthly basis.

Quote from @Gian Pazzia: For properties that small, you should budget $450 per property and use software like the one below from a trusted brand that has been in business almost 25 years. 

. - Try to put all the steps of a deal in a project management software like Asana, Monday, etc.

Any recommendation for a good preferably open source rental management software that primarily handles back end accounting? 

I would not search by AI but by virtual reality type software.

Hello,I am getting all my property management documents and software in order before I buy my first rental property so that when I buy it will be a smooth transition, Beside the lease and application, what other documents should I have in my files so that i am prepared (pet agreement, inspection checklist etc.) .

I will give you some of my highlights.People in Texas complain about their property taxes at 3% ours are about 4.5%.New York in general and Monroe county specifically are very tenant friendly.Depending  on the town, the code inspectors/police can be quite anal.Since Covid and the 2020 protests we’ve seen an increase in crime in the city and therefore weakening demand in the city proper and increasing demand for the suburbs.Industry is well diversified—University of Rochester (medicine) L3Harris (defense) xerox (IT) and paychex (software/hr)) and relatively recession proof.Population growth is low and therefore appreciation (except the past 4 years) has been moderate as well.There aren’t many builders in the area so supply is relatively fixed.Home (and rent) prices are both affordable with homes typically being less than 1/3 median household income and rent being similarly affordable.For single family homes at 8% rent will cover piti with about 100$ to spare in the A areas.

But if you're using a property management company it would be tough to integrate softwares.