Hi guys,
I am running a small developer team and we are more and more moving towards blockchain development. I am technical, however, now I am more acting as business manager, CTO, bitch for everything...
Hahaha. I know how being a bitch for everything feels. I work in a small furniture business my family owns.

I need to get to a point where I can decide, what blockchain suites which project (for data storage, AI, big-data, BI...) and I need to understand more of the rough technical backgrounds like lightning... not only for bitcoin but overall.
I am sorry to break your bubble but you might need to rethink why you want to use a "blockchain". Most businesses and projects do not need one.
I went through all Udemy Courses and a few other ones but those are all just scratching the surface.
Can you recommend good courses, books or other resources in that regard? I don't need deep coding understanding, just from the architecture side.
Thanks for the help
Michael
A good place to start your Bitcoin journey is in the developer documentation,
https://bitcoin.org/en/developer-documentation