Multiple Problems with Custom Theme

Hi all, I’m sorry that I could not be descriptive of my problem(s) in the title but that is because I have had many problems with my uploaded custom-made WordPress theme.

I would ask you all to visit my newly-made website at http://www.mixedniches.com for consultation and inspection of the following problems.

1) I know that my theme shouldn’t have more than one page(without using wordpress database) but how am I supposed to add the CSS to the other pages?

2) The content(title) of posts appear to be on the left of the screen, and are left out.

3) When using the basic 2014 theme, or any other for that matter, the wordpress header(the thing which says “Howdy, Username”) is there. But I can’t find it on my website’s top and have to login to the dashboard using wp-admin.

4) I had a contact pop-up for the contact page(located in index.html only) which does not appear, even though it is right there in the code. (look at the screenshot of the contact modal at http://imgur.com/zQ2aeTJ)

5) In my index.html file, the header was fixed at the top throughout scrolling(navbar-fixed-top) but it becomes static on the website.

6) In index.html, I also had “Read More” buttons beneath the 3 posts at the bottom(“Welcome to the Blog!” and the Greek Text) but now they are getting hidden because of the scroll bar ending.

Whoa, those are a lot of problems. Any help whatsoever will be appreciated, and thanks in advance.