I'm not up-to-date on what is out there in free quilting software, but Electric Quilt has options to print out paper piecing units.
I usually do the graph paper thing, and then go to the local office supply store (or library) and use the printers there.
Here's a great resource for basic shapes and grids -- Bearisgray was the first person I saw link it and so I think of her every time I use it or repeat the link!
https://www.incompetech.com/graphpaper/
There are basic grids, hexes and tumbling blocks and other things you can adjust/print to the size you want (make sure you double check your print outs and your print settings that they are as shown and not adjusting themselves!).