Comment by zenoprax
This is heartening - I'm about to start with the daily challenges today and document my experience and that sort of thing.
Any other suggestions? I have sysadmin experience as a homelabber and at work with a small company as a "tech lead" but have not yet had the chance to do it full time in a larger company. Currently focused on back-filling knowledge gaps and adding certs to support my existing experience.
Sad Servers is great for trying out how to fix scenarios that you would probably run into while working in the real world.
If you are looking into more of the "people" side of things, I would HIGHLY recommend Never Split the Difference by Chris Voss [0]. A big part of being a team lead and/or working at a larger firm is understanding where people are coming from and then convincing them that your solution is "win/win". The book is great at highlighting multiple different tactics to do that.
Turn the Ship Around [1] is also great at giving examples of how to "change organizations in place". If you end up at larger firms, there will be a LOT of legacy infra and processes that you may want to improve. Marquet gives excellent examples of how to change things WHILE ALSO getting buy in from the team.
0 - https://amzn.to/48dBSn2
1 - https://amzn.to/4pfL2Wb