How did I start? CPF when I joined back in 03 when it was friendlier. I still use it for info on modding.
That, plus screwing up! 
Learning by my mistakes. Best to practice on a junker light first and if you ruin it, so what? (I got good at my antique radio restoration hobby also but I won't tell you how many times I got knocked on my arse also!!)
I do not, and have never owned a lathe. Only access I have is to a bench grinder. Otherwise, I use all hand tools. Same fixed income boat as you so I still use the tools I had from before I had to quit work in 2004.
You can do it though... here's a plug for the mods I did. Needs to be bumped so others can see it anyway. Hand tools only.
The rush that you get when your mod lights up and works... nothing like it!
Start out simple, go slow, walk away immediately if you get frustrated and come back to it later, and learn the best time of day for you, when you feel the best. My best mods come at 3 in the morning; I'm a night guy. I do yoga to keep centered-nothing like it for me-so modding right after a yoga class is good, right after I've meditated and gotten in the 'zone.'
And don't listen to the rich guys on CPF that tell you to spend big bucks! Take what you need and leave the rest.
Rich