> The things I want to do, are they ‘goals’, ‘tasks’, ‘phases’ or ‘executions’?
The page I linked to is pretty clear about which is which and what they do.
> And do I manage my dependencies in ‘dependencies’ or ‘dependencyManagement’?
You list your dependencies in dependencies, you manage them in dependencyManagement. But it's clear in the documentation, and if you're looking at a tutorial from 10 years ago then it'll still be accurate.
There are confusing things in maven. But documentation and backward-compatibility go a long way, and I really think the fixed build lifecycle puts it head and shoulders above a lot of alternatives; the cost/benefit of each project having a slightly different set of build commands just doesn't stack up.