Ivanicof Help Needed

Let me start by apologizing because this is all completely new to me. I have been able to fumble through and get myself most of the way there but I am having difficulty with a couple key things. I will try to use the correct terminology or at least explain it the best I can.
First, I set up menu pages and I even created a couple new posts that display as you scroll down the homepage under the menu. I have created categories for each of those posts that relate to one of the main menu pages. I was hoping that while the most recent posts appear on the homepage, they would also be listed under the individual page that cooresponded with the category, so that when I clicked on a page in the main menu, I would see all posts that were categorized under that heading. What do I need to do to make that happen?
Secondly, is there any way to change the color of the background and font for the most recent posts on the homepage? I only see the one area under “customize” to change colors but none of those tabs actually do what I am looking for.
Lastly, does this theme accept a comments section? If not, no big deal, I just did not see it anywhere.

Thanks so much for any assistance you can provide.

Scott