Hi, I ´m an engineering student, and this is my first attempt to model an assembly in Fusion 360.

As for the print itself, I don´t own a 3D printer just yet, so I can´t verify, that everything is working together. I suggest you print everything with cubic infill because it´s best for handling indirect forces. The press plate should be printed with high infill %.
Nothing should be needing supports.
As for assembling it:
1. Press the holder body into the wood, the sticking part should be in front ;)
2. Put the press plate between the threaded hole and the wood
3. Screw the threaded shaft through the threaded hole with the Screwing wheel on it and make sure, that it´s pressing on the wood with enough force
4. Put the spool shaft through the 15 mm hole and put the Press fit wheels on the ends
5. Happy printing!

You´ll find a single STL file with all the files oriented for the Prusa MK3 along with Fusion file so that you can adjust it yourself if you´d like.