As a 3D modeling kinda-expert there are some free programs online like Tinkercad.
This one is pretty easy to get the hang of, but I haven't tried exporting files for it.
3D modeling does take some time to get the hang of though. I would watch some tutorials online and just start slow.
If you want to invest some money in a software I would recommend Zbrush for more natural and organic modeling.
I personally use Rhino, which is more for engineering and industry.
If you're looking for files to print I would head to Thingiverse and get started
But not to get your hopes up, but hairing 3d printed parts is a bit tricky depending on what material you use. I know my printer uses ABS plastic and you cant really use a rehairing tool for it since there is no give in the material. What kind of printer do they have, and what does it print with?