For sure there are players that don't use any software. And i definitely wouldn't say it is necessary. The first 2 pieces of software i purchased when starting to learn were PT3 and SNG Wizard. The initial appeal of something like Poker Tracker , was just tracking my own progress, graphs, etc. i started with the most basic HUD, and as i learned more about stats and how to interpret them started adding more things that i felt were important. At first was only playing 1 or 2 tables, so was easier to pay attention to the action, but as you start playing more tables, a HUD can be pretty helpful.
I'm a big fan of software, anything that can help me learn, or make things easier are great. I'd say read the forums and learn your stats and how to interpret them. i experimented with all kinds of HUD's, custom stats, and finally found 2 that make sense to me and i understand.
As far as self analysis, something like Leakbuster is great for learning your optimal stat ranges. It has been one of the best things i have purchased for learning cash games. i started with a million leaks, but it has helped me eliminate alot of them. Still alot of work to do, but it is a cool program and has some great content.
So, i'd say maybe do a couple of the free trials for HM2 or PT3/PT4, maybe if nothing else at first to chart your progress, and see which program if either you like better. you can always turn off the HUD feature, or just start with something really basic like VPIP/PFR and AF.
Good luck!