OK, to find out the best route to take we should ask, where do you want to get to?
Are you looking for software to process .jpg pictures straight out of camera, with no more than a little brightening, minor tweaks to colour & a quick crop? Irfanview (fast & free) will do that.
Are you looking to (maybe eventually) process faw files, manipulating them non-destructively, tagging them with keywords to search through later (maybe years later) and perhaps printing or displaying them in some other way?
I use a variety of software, including Irfanview when I want a quick resize etc. Although you're a beginner now, I'd recommend choosing something you can work with later as you progress, rather than having to re-learn yet another software package. Worth bearing in mind that all the software makers offer free trial periods to evaluate their stuff. Having used both free and paid software over the years, I'd now choose paid for features, reliability, continued compatibility with my equipment. Free can be extremely good, but can also be clunky, awkward, deficient in some way that's important *to you*.
So what do you want from your software & where do you want to be with it in 5 years time.