Finally, someone who understands me!
Let's hang out, guys! (I don't know myself what means...)
Anyway, I think I'm pretty much settled on Welsh as my preference, and I more or less know how I'd proceed... Well, I also need more financial security, because even if I can start off for free, I think I at least need to invest in some beginner readers.
Also... well, I don't think I can stop once I've started on Welsh. Other languages have caught my fancy. I've foolishly subscribed to a professor of Old Norse on Youtube, and now I find Icelandic very appealing.
I once thought that I might settle and find stability with some basic widespread languages like German, especially since your language-learning ability is supposed to decline with age. So I thought in my thirties I'd just practice and deepen what I've got. But I guess it's not to be.
As far as German, what I used at the start, with some enjoyment, was "German Demystified" on Amazon. "With some enjoyment" is because I believe that all language instruction at some point overstays its welcome, unfortunately, and it's all a matter of how much patience you have.