I've always heard good things about Darktable as an alternative to Lightroom, but I do not have experience using it so irdk.
Alternatively there is always the high-seas version of Adobe CC. I wouldn't be too concerned with the ethics of it seeing as this is Adobe we're talking about 🤮.
been using Darktable for years now. had the same trouble with it as people going photoshop to gimp have at first, because my brain was all in lightroom. once i sat down and watched some videos of people explaining their own darktable process and experimented new workflows. it became everything lightroom was, but without the constantly scolding me about bumping my subscription adobe did.
I've used darktable but do not like it. I used it for a while before I got a "demo" for light room classic. It took me like a hour and I figured out how to make my pictures exactly how I'm imaging them with LRC. Darktable is not intuitive to me and feels too clean and scared to just give me a table full of sliders and values. Masking also took like 30s to figure out and now it's so easy where I still can't in darktable well.