Think of the first property as the practice period and the BRRRR as the real game day where your practice will pay off. 

I've found one on Amazon:The Lease Manual: A Practical Guide to Negotiating Office, Retail, and Industrial/Warehouse Leases, Second Edition by April Condon (Author), Rodney J.

Find Brandon's videos on YouTube for the "four square" method of analyzing homes and practice.

It's a great practice to share leases and learn from other landlords. 

I concede I'm a bit conservative but look in the mirror and tell yourself honestly that you have practically no real estate knowledge and no real estate experience and then ask yourself is that's the footing you want to be on as a basis for totally disrupting your life and risking $250k. 

But the sooner you get practice/experience the easier EVERYTHING in life gets! 

Regarding flooring and shower pan options, a shower receptacle paired with subway tile and small 1/2 inch tiles for the floor could be a practical choice.

I have heard that onsite staff could also be the employee of the 3rd party property management company, but just wonder what is the normal practice?

Here is the NAR (National Association Of Realtors) code of ethics standard of practice defining a client and a "CUSTOMER".

@John Weiss This is standard practice for the property management industry.