Hi Isabella,
Making the logo/site title and menu inline is easy just navigate to Theme Options > Header and set the Layout to Inline
However, before this to work, first we need to remove the Revolution Slider banner you added there. I think you/we added that via a custom template in the Child Theme, I can’t confirm it now because I can not see your Child theme files in the admin dashboard, we need FTP credentials, please provide in a secure note if you don’t mind.
Second, you need to reduce the font-size of your menu (Theme Options > Header > Navbar Font Size), and reduce the font-size of your site title as well (Theme Options > Header > Logo Font Size) so both of them will fit in one line.
If we can do these two things, the issue of extra space in the header and making the site-title and menu inline will be solved.
We will tackle the other issues after this, we will focus on this for now to avoid confusion.
And I recommend, for now please clear and deactivate all your caching feature/plugin, so the changes we are making will take effect immediately.
Thanks,