I genuinely admire that you are motivated enough to get involved with UK politics - and I wish you all the best. You've no idea the disappointment I had in the LDs though - I cheered them on in a handful of successive elections (they ousted the Tories in my home constituency West Aberdeenshire and Kincardine in '97 much to my family's delight) and in the run-in to 2010 was convinced they could rise up to challenge Labour and the Conservatives.
And then to join the Tories - it just boggles the mind, I cannot fathom how anyone didn't think "won't this completely kill us off?". For one this basically lost them the foothold they had Scotland (my home constituency was lost to the SNP, for example) and whatever was left of the younger supporters who weren't turned off by the association with the Conservatives were then burned by the Tuition Fee saga in England.
We'll never know what would have happened with Brexit if the Lib Dems were still in the coalition. But they completely capitulated on a single extremely simple promise in 2010. Now I (a previous Lib Dem voter) have no reason to believe they wouldn't do the exact same again.
But overall, yeah you are right. I do not understand the Lib Dems. And it fucking saddens me.