I like having the ability to do a lot of tweaking if I want to ,so I have Lightroom and Photoshop. $10 a month on the Creative Cloud plan. Lightroom has plenty of great tools for organizing you files, too. Lots of people hate Adobe for instituting the monthly payment plans, but for something I use almost every day, $10 a month is no big deal.
What IS a big deal is learning these two pieces of software, Photoshop in particular. The thing is, there are TONS of online videos and articles to help you out. Also, learning the basics on Lightroom doesn't take all that long, and 95% of the time you will only want to make basic adjustments, so you really can get started pretty quickly.
All that said, there are all kinds of very useful processing choices these days. I have heard great things, in particular, about ON1. You can download a copy for free trial, if interested.