How do you select a region in Logic Pro X?

That is where a manual might help: it shows you what parts of Logic are called. If you don't know the name of a thing, then you can indeed only learn from pictures, which is a limitation. YouTube video's are of very differing quality, and is not as complete and ordered as the manual is - even though the manual is not fully complete either.

So, this is the tracks area:

I copied that from this page from the online manual (which I would recommend you'd bookmark - though you can find that same manual under the Help menu in Logic itself)

I have found that the online manual functions better though, and is easier to search.

The concept of selecting is not unique to a Logic. Use your mouse pointer to hover over the region you wish and then left click it. The region is selected and highlighted to denote that. This is pretty basic and you must have been doing this??

anyway unless I’m missing your point ....

I suggest you read at least the first few chapters on the manual, which describes in detail not only what a Region, a Track, a Range, a Channel, and a couple dozen other things are, but also how they interact.

If you don't understand the language, no one here will be able to help you.