alright, if you have a Mac you won't have MS Paint.
But on Gimp, you can have the pic to render on one layer and then in a new layer you can have the completed render. Make sure to use the pencil tool if you use Gimp.

If you do have paint,
Color the back ground you don't want in some bright color (you can get rid of it later) then render the character out. then you can change the bright color to white then paste it onto a new background.

Paint is already on your computer... on the start button, look under accessories... it should be there

You should unless your using a different OS.

Please don't use sms, and PLEASE name your questions other than, "please help"

but i dont have paint.

Outline it on paint, go to Gimp and click the... fourth tool. (I think) And click on the outline, take it back to paint, it dhould have a white box around it.. (I noticed that and thats how i did it once) that way, you can cut the bg without ruining the outline. If you want a solid color.. just use the paintbucket. then color it.. ta da! You got it now... im sure theres a simpler way though. XD (By the way, the tool you pick should look like a wand without the star on the end but has a yellow dot on the end.. XD)