I'm from Texas and that's pretty much how I started.
What part of the state are you in?
A few things come to mind.
You will need a sales tax permit, insurance, and I'd look into workman's comp. I have all of that. Most of the guys I run into, have none of it and are fly by night in my opinion. If you are going to work beyond your neighbors, I'd hone those skills at your place. You will quickly find what works and doesn't work.
You don't need to jump in with 100k machine to get started.. I'd find a used machine/used head and let it take the learning curve. You will pick it up pretty quick and if you are handy with tools, you can keep it running pretty good.
There really is a lot to discuss so it might be better to throw questions out there. I could tell horror stories all night around a campfire about the dumb things I did or the lessons learned the hard way. I've been at this almost 20 years and I'm still learning something new everyday but luckily I think I've got the machine operation part down pat. I was blessed to have my own place and an in-laws ranches to practice on as well as neighbors' properties. That's about all one can hope for if you want to hone the skills before going commercial.
I'm sure your military training will make you a natural around the machines so it will boil down to what you choose to operate and how you plan on doing clearing.
Anyway, welcome to the forums and thanks for that service!
Thanks for the welcome YellowDog
Sorry for the delayed response internet out here has been hit/miss the past two weeks. I'm in West Point and with reading all the post to answer most of my questions (Thanks again to your post/replies) I'm hoping to be up/running by Feb just gotta finish getting all my ducks in row.