How to use different title for pages

Hi! I bought two themes here - Sunnybeach and RealBusiness, and I have some questions abou Seo:

1. How can I write different title for pages?

2. When I wrote post, I see something like this in title:
- Name which I wrote for the post - and then - name of my site, all this in title in my post.

I want see title without name of my site. How can I do it?

Thank you! Dima.

Hi!
Please, give us the URL of your website.