You need make a decision here. Do you want to be moving boxes (getting stuff from suppliers and selling them to customers for a profit) or doing computer support. I would talk you totally out of trying to do computer support. You will end up dealing with people's problems, not computer problems. I've been there, done it. If you want to sell stuff, you would have to stock up on inventory and deal with overhead such as renting a store front. At the rate computer parts get obsolete, you better make sure you can sell stuff fast.
I would definetly try doing some programming. There are websites that you can bid on certain jobs, so you can start small while keeping your job and not having to come up with a major investment.
A few years ago I was running my computer business now I only do programming, making lot better money and having lot less headaches. I advise you skip the computer business stage.
My 2 cents.