I'm not sure where to start on assembling a 10-32 x .375 Socket Head Cap Screw, attached is an assembly I found. How would I be able to change the dimensions or make one from scratch?
I have SW 2017.
What is a "socket head cap screw assembly"?
A socket head cap screw is a single part.
You can edit any dimensions in this part to make it a different size or shape. Edit Sketch, and Edit Feature are the tools to use.
As a beginner, you really should work on building simple parts like this as practice. Eventually you'll be super talented with SolidWorks and won't want to waste your time making a bolt.
If you have the Toolbox add-in for SolidWorks, grab common hardware from there. If you don't have Toolbox, check the library here for hardware you need, or go to a site like mcmaster.com They have lots of stuff like this and the models are generally made quite well.
You have SW2017, but it is the educational version. You won't be able to open any files saved with a commercial license.