Minor issues (hopefully) that may involve coding

My blog is self-hosted and is located at https://www.candacemarra.info. I am relatively new to wordpress and blogging in general, plus I am overwhelmed and having difficulty comprehending a lot of the common terms used in blogging. So please bear with me. I also don’t know any coding, so I really need someone to spell it out for me pretty clearly.

Here are the issues:

1)The top navigation menu where it shows my rss and twitter icons is messed up. It messed up while I was replacing the template-specific ads with my own adsense ads. I noticed on the demo of this particular theme (Karmela), that it does the same thing, so it’s not just me. How could I edit this code so that it goes straight across the page and the menu items and icons are where they belong? I’m assuming this would be in the css file and/or in the header file?

2)The theme options page allowed me to add the twitter link in the top navigation menu, but there was nowhere to add a facebook link, which I would like to do through the theme options page, as I don’t want anymore sidebar items. Plus, a facebook icon would look so good up there. Which file would I have to edit to add this? Could I just copy the code that was used to add the twitter icon, only with my facebook info?

3) This is kind of a dumb question, but I can’t figure out avatars. I don’t even know what the difference is between an avatar and a gravatar. I installed an avatars plug-in, but I still can’t add an avatar. Do I have to set up a folder somewhere? I tried uploading my own picture to use as an avatar, but all I get is a red x.

4) I don’t know when this started, because I didn’t try to do this until after I already had all my plug-ins, but whenever I try to delete a picture from the library, I am taken to a 404 error page. I suspect this is somehow caused by the bulletproof security plug-in, but I can’t be sure. Either way, is there an easy fix for this? Does it have anything to do with user permissions? Edited to add that I am able to delete posts. Also, it doesn’t matter whether I try to delete the picture from the posting area or via the library, it will not let me do it.

I’m sorry for having so many questions. I tried to be as specific as possible. I hope I’ve been clear in what the problems are, and that someone has the answers. I’ve been working on this blog for three straight days now! Thank you so much for reading, and kudos on an excellent support platform.