Welcome Joey.
First advice would be to get yourself to the gym. I understand you may not feel comfortable doing that, but most of us who walk into it for the first time feel that way.
If you can't get yourself there, then I would recommend firstly finding a proper eating plan and an exercising regiment. I'd look at simple doing that before you run out and buy a bunch of boxing stuff. Try something like that and see how you feel. If that feels good, then maybe then look into a bag and some gloves and so on.
I do think it is great of you to make a post on here, and it is a first step towards getting healthier. The next step is getting your ass in gear.
I wish you luck with it and hope you stick around and let us know how it goes.
