People wouldn't believe how many deals are lost at what I call the "decision phase" where a lead from an offline marketing campaign goes to research you, and doesn't find good credibility online (which includes the website). 

Is looking online at sites like LoopNet sufficient? 

This is what I did for a cabin I built in Gatlinburg:  We took a few royalty-free photos of the area off of the internet, and submitted them to an art site online whereby they make a painting of the photo.  

Many PHAs allow you to apply online, but some may require a paper application.

Rentmarketplace.com helps with the online application process.

I would go online and check other rentals in your area to see what other management companies are out there, and start contacting them.

I setup one QBO (Quickbooks Online) account to handle multiple LLCs. 

From the little I've learned, it seems like it needs to be hospitals with a high need to bring on more staff/nurses but I'm not sure if local clinics would have that much of a need.

Theres a lot of place online to list like apartments.com, facebook marketplace, realtor.com, trulia, rent.com.

We currently have 105 units and are using a variety of excel, google docs/sheets/calendars, apartments.com (ads and rent collection), docusign and QuickBooks online (which we would like to keep).