How do you effectively change SEO data after a website redesign?

I built an online portfolio with Nick Petit in the "How to build a website" stage at the very beginning of the HTML track. I obviously didn't have any work or content of my own yet, so I used Nick's and basically built the exact same layout. Now that I've gotten a project under my belt and redesigned my website, I'm wondering how I can get the new, relevant information to populate in search engines (although I've used the same url).

Here is my website: http://taylorplante.com/

It's a custom WordPress theme, and I've downloaded the SEO plugin recommended by Zac Gordon, changing the data on each page appropriately. Unfortunately, the data is not showing in Google or other search engines, I instead see my old website title and data from the header, although those files are no longer present on my live server. Alongside that, I decided to hardcode a meta description on my front-page.php file in the head section, which I've seen populate in Bing, but still no luck in Google.

One thing to note is that the header.php file that I've included on the rest of my pages is not included on my front page. Do I need to find a way to include that header file on my front page and manipulate the CSS to get what I already have, or does it not affect my SEO to have unique header markup on my front page?

Lastly, I have done most of the paragraph style writing on my page in the markup or using custom fields, and I think there is a related error connecting my SEO info I submitted via the WordPress plugin to my posted data in WordPress.

Sorry for the long description, I thought knowing some of these variables may help.