I used to volenteer run a local branch of CodeClub in the UK - a supranational charity that produce their own courses based around Scratch, HTML / Javascript and Python.
It was my first time doing anything like that and found that CodeClub were really supportive and had a heap of resources for us to use.
I have been volunteering at my local codeclub for about a year now. Loads of fun and they have a full online curriculum[0] full of resources that cover everything mentioned in the parent. They also recently partnered with the raspberry pi foundation so I am sure we will see more crossover in that space soon.
Code club is a volunteer lead international coding club, maybe see if you have any local clubs that you can support or if you can find some people that would be happy volunteering a couple of hours every week to run one at a local library (or similar).
All of the resources use web technologies, so they can learn python through a browser at a library computer without needing their own resources.
Another thing I have been part of is OMG Tech![1] which holds events every two months with the aim of exposing children to tech that they wouldn't have experienced otherwise. So imagine taking a bunch of kids from low decile schools and having fun with 3d printing, robotics, coding, science experiments and more. The theory being that a lot of kids don't go into tech because they just don't know about it, have never experienced or think it is just too hard. So just showing them that they can do this really cool stuff goes a long way.
It was my first time doing anything like that and found that CodeClub were really supportive and had a heap of resources for us to use.
Worth a look: https://www.codeclubworld.org