Customizing the "custom homepage" for Nelo

Hello,

I am trying to customize Nelo’s "custom homepage" form in the admin section to look something like this:

screen shot

or look at attachment.

And then how to reflect this form in Nelo’s template?

unfortunately I don’t know how to proceed because this theme has no documentation that can direct me how to proceed. I am not a PHP expert at all.

Is there any documentation that can help me? or maybe support can help me?

Thanks you guys.