How can I add a full search bar on the Crave theme?

[butcherssecrets]

Hi, can anyone help me, I'd like to add a a search bar just beside the logo. I'm using Crave theme. I do not have much knowledge on anything, so if anyone can guide me through that would be great.

See image below this is what I wanted achieved, also while at it, I'd like to make the navigation menu at the bottom centered, I can't find any option to it. Please help, thank you very much!