Few questions

I got my Samsung Impression about 2 weeks ago. It's a nice phone but I do not have a data plan so I am very limited on what I can do. I was looking at other threads and I saw TKFE, which I do not understand at all so if someone could explain that I would appreciate it. I also saw QPST, since TKFE requires a data plan (correct?) I was more interested in QPST. I don't know how QPST works either. This is the first time im doing stuff like this to my phone and I probably don't want to get it bricked because, well, my dad would be furious. I searched for threads but the information I found was not clear to me so I didn't understand it. An explanation on what these terms mean would be very helpful.

Edit: I might get the $10 data plan (which is unlimited internet i believe..?) some time in the future. I looked through that MEdia Net and it is not good at all. Is there another internet i can download for the phone? And is there a way to get free internet without a data plan?