For professional use unfortunately Lightroom has no equal. I say unfortunately because I hate paying the $10/mo subscription fee but I have yet to find something better and I have tried nearly all of the mainstream alternatives out there. TBH, none were even close.
For high speed batch processing FastStone is a good free program, I still use it to this day to process hundreds of images after a shoot to send previews to clients. It can also do some very basic color correction. Paint.Net is another free program that I use for simple editing, but only for finishing touches after post processing in Lightroom.
Moving up the chain a bit is ACDSee, I used it many years ago, it does cost but back when I used it, it was pretty well rounded and beginner friendly. Here is a decent article on Lightroom alternatives. I have tried them all at some point and none come close, but if you are just starting out then one of them might work for you. For me personally (and the reason why LR still has no equal) each of the 'alternatives' was missing something you just take for granted in LR; such as performance of
lightroom mod apk latest version, accurate raw processing, copy/paste settings, presets, batch processing speed, organization, etc. Each one has some of it but not all of it.