They then send out what properties they have under contract to their list of buyers hoping to make a spread on the deal.

A lot of properties don't enough spread to even meet that minimum, so it just ends up being the new assessment ratio.It's actually really easy to fill out the application and submit, but they will not respond and tell you whether or not it's been approved.

Also, are there any social media websites with groups that I could network with that highlight investors & wholesalers? 

Do understand that you will have to pay mortgage insurance and the rate will be much higher then if you put down 20% or more. https://singlefamily.fanniemae.com/media/20786/display

I've been focusing on fourplexes as a first investment to spread vacancy risk but the inventory in my driving area is pretty low.

If you do have money to invest in your wholesaling business, then you can pull lists from Prop Stream or List Source and skip trace them, use bandit signs, social media advertising, Google/Bing ads, Direct Mail, etc.

You are watching too much content on social media.

Reading the book is great; however, your market, your projects and you person experience will help you create a deal with better spreads and everything else by getting those bids and use that knowledge for the current job and future jobs.

Become a syndication Co-GP by lending the escrow funds for the true GP where you receive 1% of the GP share of project upside, then create website and social media marketing materials where you hold yourself out as THE GP for the syndication.5.

Excellent customized spread sheet.