Start with the top two stickies in this forum, and also browse through the other topics:
http://www.ethicalhacker.net/component/option,com_smf/Itemid,54/board,22.0/This general "How to get started?" has been answered many times already. We can provide much better direction if you take some time to, do some research, and ask more specific questions.
If you really only know a little about computers at this point, you should probably set hacking/pen testing as a long-term goal. You need to develop a good a solid understanding of systems, networking, and applications. Try coming up with more manageable goals, so you don't burn yourself out and/or become discouraged. For example, start by focusing on obtaining your CCNA and landing a network admin job.
Python or Ruby would be good languages to start with. You can find crash courses in both here:
http://learncodethehardway.org/ and there have been many other good resources posted elsewhere in the forums if you're interested.