So I saw this posted on /pol/ regarding who is organising the NoKings riot protests.
I looked up his name and immediately recognised the guy from this /pol/ image I have saved:

Found the original article at the Times of Israel
Archive
The article says they are Erza
Levin & Leah Greenberg, and they are influenced by their Jewishness.

It looks like they have been organising since Trump first got into office, and they have set up an organisation called
Indivisible. At Indivisible, they encourage people to form their local chapters for self-organising, um, locally. So this must be how the NoKings was organised so quickly all over the country; they have the infrastructure already built.

An example of the group's earlier campaigns during Trump's first term was when they used their group to get their members to protest and generally pester Republicans who supported Trump's restrictions on travel to the country from 7 Muslim countries.
They are former congressional staffers, and very influential,
even being in Time magazine's top 100 influential people in the world 2019. This likely explains how they secured the Walmart funding. They take donations from local members.
They have refused to declare how much funding they receive from large donors.
According to Wikipedia, they founded Indivisible to be like the Tea Party and have local chapters.
The following is archive link to their
direct action guide, which is how they got going. In particular, here is an archive link is to their instruction on
how to pester politicians
Here is an example of what their guide instructs for behaviour at town halls or other public meetings:

This is where the protesters are getting some of their money, per reddit comments:
See above. I was working on this post and by the time i saved it, I saw that the news had already broken on the thread!