Knock on the door, YES that simple, :) 

In response to your concerns, first thing to know is that investing in real estate never comes without risk and it is not as simple as some online "gurus" make it out to be.

Use people specialized in this field so that you are not caught up in any unnecessary details but can always make simple transactions without any difficulty.

Hello @Forrest Brown,I propose a simple process for deciding whether to sell or hold based on the goal of financial freedom.Financial FreedomFinancial freedom requires more than replacing your current income.

I've begun volunteering with Habitat for Humanity to gain more confidence in DIY improvements. 

My mantra for my life is “keep it simple Suzie” and that request does not meet that criteria.

Also, I would be very concerned with thinking you can DIY your first renovation.

Run  some 220V wiring in pvc underground (licensed electrician) to power a good pump if you have space/amperage reserve in your electrical panel. 220V requires less current to run than a 120V for the same power, so it's more efficient.This guy has a lot of good videos on diy yard drainage systems.

If you state the minimum requirements, such as the min credit score, min income, sending your rejection letter, can be as simple as stating they don't meet the min stated income or credit requirements. 

Biggerpockets has a simple calculator for rentals that you can start with.