Starting 10/1 i will have a vacant unit in each home and I am considering trying airbnb in my guttenberg home and maybe a travel nurse housing in the Hackensack home  (10 minutes from Hackensack Marridean Hospital).

Even after I start flying again I will have plenty of time to persue (and close) real estate deals. .

I have considered this, but due to Denver being such an expensive market to get started in my current plan is to keep buying using personal loans to secure the property for less money down.

Quote from @John Jasko: Yes, and I was brought in to the deal by a 3rd party money wrangler who has since washed his hands of the whole thing.  

I've been an agent for 3 years now and I've closed two deals, but want to start using my license more, so I'd love to hear how other agents got their business rolling!

In the last 2 months I've had to start the eviction process on one of my S8 tenants.

Start by reading the Ultimate Real Estate Investing Guide: https://www.biggerpockets.com/guides/ultimate-real-estate-investing-guide/introduction2.

When should I start the mortgage preapproval process for our upleg?

It would be at 75% LTV with rates as of today starting at 6.3%. 

When starting, I say "borrow as much as you can for as long as you can."