I totally get why you wouldn’t say Arch is fun. I’m not sure if I actually like arch or if I’m a masochist, however I will say, I learned a lot about the whole OS by installing it, and fixing it when it broke. It made me much more comfortable with using Linux. I haven’t used it in a couple of years, but I am thinking about reinstalling it. Nostalgia is a bad thing :-)
I like the ideas some other people mention. Specifically: read about your specific hardware and the distro of Linux you want to install. Then, make sure you are using as many open source cross platforms apps as you can, so when you do switch, you will be in familiar territory. I do think the criticisms of Ubuntu as a bad first choice are interesting, and maybe true, but I wouldn’t over look downstream distros like Pop!_OS. It’s Ubuntu, but with Flat packs and a distinctive Desktop Environment. Mint might also be a good choice, I know lots of people who like it (I don’t personally, but to each their own).
When I started on Linux, I installed Arch on an old MacBook. In those days apple was using amd64, but they were not friendly with Linux or the rest of the computing world. However it was older hardware, and the Arch Wiki had a great page on how to install Linux for that particular configuration. Arch is not a beginner friendly distro, but the wiki is fantastic, and so well documented.
But my main piece of distinctive advice is just do it. If you have read a few articles and have a pretty good sense of what is required (and are running common, last generation hardware), just jump in. You will probably never “feel” ready, and you will come across unique problems that no starter guide will prepare you for. So just go for it, and learn along the way.
Is RDJ really a good casting for Doom? I like RDJ, but, this doesn’t seem like a good role for imhis usual schtick. But I am willing to admit I am wrong.