BIRT, training/basics to get started?

New to BIRT report writing: stumbling through on my own. Wondering what kind of basics trainings (even just YouTube or LinkedIn learning, etc) or cheatsheets you all use. So far the trainings I have found all assume I've got understanding of writing in programming language but I don't. I am a very quick study, just need to understand the building and updating reports: operators, when to us what expressions, data cubes, aggregations, groups (when do I have to group data to work with it?)
Any help would be greatly appreciated. Cheers!