Hey man, you should check out a PC Grow, or even a rubbermaid growbox. You should definitely keep researching grow boxes and the math behind them. You will need to calculate how much light you need, how much CFM per fan/exhaust you will need, etc etc.
I'm still on my first grow box, but honestly, I've been researching it for years. I tried jumping right in a couple years back and it was a disaster, complete waste of time, money and resources. You will be much more rewarded if you really do your research and reading. Lots and lots of reading. Sketch it out on paper, does everything make sense to you? Go look at other people's grow boxes. Do you know why they have that fan there? What about the size of that intake hole? etc, you get what I mean?
Keep that motivation, just research so much that you can build a growbox in your sleep.
Then, when you start building your growbox, you realize that it's about 50 times more work than you realized and inevitably go back to researching and reading during your own construction. This is a good thing, though. You're almost there.
It's a lot of work, man. You get out what you put in.
Good luck! Hope you get on the right track, and be safe! Safety is key... you wouldn't want to lose your house over some shoddy fan wiring.. it's happened plenty of times.