Any suggestion about a course or online material to be able to understand this? Would like to understand it but quite lost to be honest.

You are probably an exception: self motivated individual. The rest of us, which I assume is a big majority: prefer video over text, are more engaged by visual interactions, and still found big parts of this material hard to grasp, not to mention the preference for the free availability of the material.

Pretty sure this will help them move in that direction:

https://www.khanacademy.org/donate

Could you name a few that you think are worthy?

Team of 3 building aggregator for online car ads in Latam country. Target is to make a transparent price listing based on actual online offerings. https://carropedia.con

Not about lambda, but I had the opportunity to read the full details of an ISA contract from other school and there might be some times when student will be mandated to payback even if they don't get a job. Related to this: someone in Reddit is trying to collect the docs..