The TK-3230 is a "pre-programmed" radio, as in that it has a bunch of Part 90 business use frequencies programmed into it that you select using the menu options.
There is no publicly available programming software for that radio.
There -is- an option to have Kenwood program it for something other than the preset 64 channels it has. However, it'll require a trip back to Kenwood for option L-1077 ($25).
The radio does have both Part 90 and Part 95 certifications, as well as wide and narrow band capability, so it could be set up for GMRS.
But, why?
1.69 watts output. You'll have to send it back to Kenwood every time you want to change something.
There are better options out there if you haven't already spent your money yet. If you haven't, get a radio that can be programmed by yourself. As you start off in GMRS, you'll find that your needs will develop and change. That usually results in wanting to change how your radios are set up. Having to send them to Kenwood each and every time is going to get old really quick.
But, your money, your choice. Looks like a decent little radio. I think you'd be happier with something a bit more flexible.