Any tips or advice moving forward?

Yes on lease and it will help you with your mortgage app, make sure you deposit the rental money and document all transactions well for the bank as proof. 

Any tips for getting a mortgage with putting 20-25% down? 

There are several of them. https://certifiedtaxcoach.org/five-tips-to-avoiding-the-tax-hazards-of-renting-to-relatives/#:~:text=Rent%20at%20Fair%20Market%20Value&text=If%20they%20rent%20below%20fair,for%20more%20than%2014%20days.

Thanks for the tips!

Along these same lines, an app like Venmo may work with a prepaid card (registered to a network brand like American Express, Discover, etc), but the issue with the daily/monthly send limit would be an issue I think. 

I will be using Bigger Pockets' resources to reach out to agents as well, but any tips/ advice in getting started would be appreciated!

We aren't giving up, but we would love some advice/tips on securing private money, maybe we are just looking in the wrong places.2.

Orange County and the southernmost tip of L.A.

Thanks @Caroline Gerardo, for your tip on acquiring as non-owner.