[Theme: Zenbu] How to modify?

Hello,

I am trying to do my first website. I have read and watched many tutorials about wordpress, but none answers how to modify this theme.

– I would like to add a picture on the head of the webpage.
– I would like to add a second “Our Services” section under the first one
– I would like to eliminate other sections

Could somebody help me telling me how to do one or all of these things?

I would appreciate it very much!
Thank you!