GoPro Hero Black 4k Project/Import Settings?

I've tried to import GoPro Hero3 Black MP4 footage into PP5.5 but only the audio imports so I'm assuming PP5.5 can't handle MP4's.  So, I'm having Cineform, a GoPro product, convert to AVI which is easily imported.

However, I'm not clear on how to set up a project for GoPro 4K footage.  Indeed, I'm not clear on the implications of the many choices one has when setting up a project.  If I choose the wrong one the project won't work?

Thank you!