[Theme: Patchwork] Centering nav bar, and why are my fonts being overridden?

Hi everyone,
Keeping it short and simple:

1) I need to center my navigation bar and am finding it impossible to do so. I have tried multiple things (tweaking the left and right margins to auto, using text align, etc) but they aren’t seeming to work. Perhaps there is something that I don’t realize is overriding my coding.

2) On the same note, my fonts were displaying perfectly until I added some social media links into a widget. Even when I take them out now, the fonts will not show up. Something is overriding the codes.

I’d really appreciate any help I could get with this. Thank you!