I am alone. I want to do it alone.I don't have much friends...how about a Joule thief?
This will help greatly with you and your friends. It allows "dead" batteries to light white leds.
The build will also teach you about inductors, and winding your OWN inductors. Transistors, point to point wiring.. Just a good project to get the brain working:
http://www.bigclive.com/joule.htm
Here is a member that used one for lighting his pet mouses' cage:
http://forum.allaboutcircuits.com/showthread.php?t=54028
Okay.You will need the skills learned from the joule thief before even THINKING about building a DC to DC converter.
And, it is not possible to go from 12vcd/12ah to 24vdc/24ah..
It doesn't work like that. If you double the voltage, you will lose at least HALF the AH.
So the 12v 12AH would be less than 24v 6AH
That is why I told you about the google calculator. It will help save you time.I don't want to waste time.
Don't worry, you've got plenty of time ahead of you. No need to cut corners--It will only hurt you in the future. The best thing I can suggest is to do a lot of studying before really building any major projects. If you want to learn electronics, you need to learn the basics first. Once you understand how electricity works, you can move on to more interesting projects.I don't want to waste time. I want to learn electronics at a very young age as much as possible.