The goal is to build & sell, but worst case scenario maintain the property for a couple of years if it doesn't sell.

I do want to own properties and build a nice portfolio.

Earn money, build your credit, save up, and invest wisely.

By nothing I mean no damage to the unit, rent on time, and good communication. 

He wants to purchase a single family in LA county that meets criteria in regards to zoning and size in order to to build 4 homes/units.

Office buildings have no such backstop. 

Get rid of debt, build a budget, and save.

I see a lot of discussion here about maximizing profits and adding clauses to leases so that tenants take more responsibility for things, but I'm interested to know some advice about how to take better care of tenants to build up a good reputation and practice business in a fair and compassionate way.

I need money to build this facility.

House hacking, especially in a high-demand area like the Portland metro area, can be an excellent strategy for building wealth and creating passive income.