Two tiny layout changes

Hi there,

I’m building a new website with the current link as https://nikkinicolephoto.com/joey/

What I’d really love to do is:

1) Alter the font of the top menu. Preferably I’d like to use a font I have myself (ie, not on the theme’s design menu). Can I install a theme and then use it to replace the current one?

2) This is even more of a minor change; there are two lines under the header. Can I remove one line, or at least change it so I have one or two lines under the central photo as well?

Is ANY of the above possible?

Thanks