google tabs corruption

I am very new to WP, have no code skills and know next to nothing about SEO, however……………..

When I open up my site in a new google tab, the tab description at the top
shows %%sitename%%, how do I resolve this.

Also (related to SEO…..I think) when the google search results come up it shows mine as Uncategorized Archive | sitename. How do I resolve this to just the sitename and tag line.

Any help would be appreciated.