Around the same time, BP started posting YouTube videos of the ADU Guy, Derek Sherrell (see video below) which planted the seed of converting my garage into livable space.

Since you want it to be as easy/quick as possible, I'll give you three things you need to learn...as a starting point:1 - How to Analyze Markets to find the Micro-markets that are good to invest in.2 - How Money Works, so you can develop an unlimited number of strategies which will allow you to be able to take advantage of as many opportunities as possible.3 - How to design your own REI Plan by reverse engineering from your specific set of financial goals back to where you are now...then execute it by turning around and just following the breadcrumbs.4 - (OK, I said it wasn't as easy as "just one thing")...Learn what the meaning of the number sequence "1073751824" means, and how to base EVERY decision you make on the meaning of that number sequence.5 - Learn why it's so important to follow the 2 Golden Rules of REI, of which GR#1 is:  NEVER, under ANY circumstances, ever, EVER, spend your seed money (your starting cash). 

The seed money started as an SFR that I put $30K (hard earned savings) as a down payment.

YES, Tax Free is wonderful, but a Roth is just paying the tax on the seed and not the crop. 

They also fixed the lawn and laid seed/straw down.

I have about $40K of savings that we can use to start us off but I would like to see if there are other options to get more seed money. 

If you're concerned about how the yard looks, I would recommend using grass seed that is native to Texas and can handle the heat in addition to xeriscaping to save on water. 

My property operates within an HOA, recently HOA has been getting on our case for re-seeding/up-keeping the front lawn.As with most of CO, grass tends to die over winter, so here is my question: What is the best method to up-keep, re-seed and re-develop the front lawn?

Bunch of whiners.  1/2 inch of ice and everyone thinks the Chinese balloons seeded Ice crystals over Texas

Rather than pay off your debts, you could take your initial seed money to invest with a rate of return.The big thing right now is just understanding and ensuring your rate of return on any investment you do with the cash on hand is higher than the interest rate of what you are paying off.