What do i do after i buy a phone online?

So right now i dont have a phone because my parents cant pay, (we had sprint) we still owe them money so before i can start a new plan we have to pay them (which we can right now). So i decided i wanted to buy my own cell phone. I found a LG enV VX-9900 Orange. http://www.amazon.com/LG-VX-9900-Condition-Wireless-Contract/dp/B003TOMYG2/ref=pd_cp_cps_1 . And what would i do to get it started up (so i can text and stuff) ? I cant start a new plan right now can i like buy minutes for this phone or something?