The land itself is relatively flat, but undeveloped and needs to be weeded.

(check with your tax professional for this: sometimes the max deduction is a flat number... etc) You could rent out a bedroom and live for free.... 

My first 2 flat was on the same street as my condo 5 blocks away so I knew exactly what I was getting into.

However, after crunching the numbers on a potential 2nd unit, there’s a risk that my cash flow remains flat.

Here's what i have to work with:My current CA home value = $600,000I only owe $222,000 on the houseI refi'd 6 months ago to get money to upgrade the house...central heating and air/ new kitchen/ landscaping/ New electrical panel and 200 Amp service. 

For example an investor wants to use that property as a rental would be making a return of under 2% if they paid you $400k which they aren't going to do, even $375k puts them at 2% flat which is really bad, if rent is only $1700 you'd be getting offers from landlords under $250k. 

Anyway there’s back taxes to be paid for 10 years and some other stuff but the lawyer said this will be easy to make a deal with the panel.

https://www.har.com/content/newsroom/Houston Real Estate Highlights in May:-Single-family home sales fell 20.2 percent year-over-year, with 6,671 units sold, marking the second straight month of declines fueled by the COVID-19 pandemic;-The Days on Market (DOM) figure for single-family homes grew from 54 to 58 days;-Total property sales dropped 20.7 percent, with 7,917 units sold;-Total dollar volume dove 25.9 percent to $2.23 billion;-The single-family home average price fell 7.4 percent to $298,199, the first decline since January 2018;-The single-family home median price was statistically flat at $249,000;-Single-family homes months of inventory was at a 3.5-months supply, down from 4.1 months last May and below the national inventory level of 4.1 months;-Townhome/condominium sales dropped 36.0 percent, with the average price down 2.3 percent to $206,146 and the median price up 2.9 percent to $175,000;-Single-family home rentals jumped 11.9 percent with the average rent down 2.8 percent to $1,822;-Volume of townhome/condominium leases fell 4.6 percent with the average rent down 4.6 percent to $1,586.

What you want to charge are "fees" which is money you get to keep in your pocket.Some charge an up-front "pet fee" which is a flat fee the tenant pays for the privilege of having a pet.

If such a flat fee service does not exist, what are some things I should consider before investing my time in getting licensed?