I use Landlord's Cashflow Analyzer software (Canadian Edition).

If you have a property management software some of those have built in online payment structures you can set up. 

This Software can generate the legal declarations renters need to qualify for federal protection from eviction at least for now until the moratorium ends.

The book recommendations on this thread are gold.In addition to being a voracious reader, I recommend looking into careers that pay well out of undergrad, namely software engineering, investment banking, and management consulting.

Also I am in a masters program at Montclair State university for software engineering so I figured, instead of paying someone else rent, the faster I get a property, the faster I wont be paying high rents near montclair.

We are planning to launch our first project on a big scale like we already have a registered office in Michigan, and now up to purchase project management and customer care software.

What would be your suggestion as an inexpensive, or free, PM software for someone who's just starting out to use?

Customer Relationship Management (CRM) software allows you to manage your contacts for outreach and marketing.

Once you get into the bigger commercial stuff, you can purchase software specific to your asset class of choice, but still make sure you understand what that software is doing and don't just blindly plug in numbers.Hope this helps a bit. 

He assist the operations manager and does a lot of the accounting data entry into our property management software (I don't use accounting software, it all goes into our property management software - buildium).