If you can only scrounge up a few dollars for a computer gadget, check out a Rasberry Pi board.
There is a great HOW TO: on youtube.
It is not a POWER HOUSE type of computer but for a do it yourself tinker gadget, bodge together it can be an "Education in a Box" for some one whom wants to take a meander down the rabbit hole of LINUX.
Get your GEEK ON!
The key to linux is treat your keyboard like a Pin~ata, BEAT ON IT UNTIL IT GIVES YOU SOME CANDY.