I'm presuming that the fabric you want to use is cotton ?
If so, then you can buy fabric paints which will work with brushes, stencils or iron on designs.
However, you need to do a bit of background research first and you need to create some kind of stretching frame for the fabric.......since it's camouflage and fine, fine details won't be crucial, you could just lace it onto some lines attached to a fence or the clothes poles.
For a good result you will need to ensure that the fabric is definitely what you want to use, that all finishes have been washed out of it and that the paints you use are intended for that fabric.
That's it really

Artistic licence is up to yourself
Suitable suppliers ? Visit your local Art Supplies shop is probably the best suggestion I can offer. You don't need to buy there (often expensive and situated in student towns) but at least you will have a good idea of suitable products. Ebay can be awfully handy
Oh, one other thing, if you intend to use a dark fabric as a base, be aware that subsequent dye won't always give you the colour it says on the bottle. Like adding red on top of blue in primary school.......it won't give you red, but it will give you a kind of plum. Light fawn is a good base for home made camo, white is a pain to do properly while the fawn doesn't need total coverage.
Is this of any help ?
There are lots of ways to print fabric, blocks, screens and the like, but for camo just painting it on with some overall idea of a design is much easier.
Best of luck with it
atb,
Toddy