Modifying the title

Hi guys!
The WordPress theme I’m using shows the title in a way I don’t like. The blog’s name is shown before the post’s title. I want the post’s title to before the blog’s name. I’ve tried inverting the php code that calls both of this elements.

It worked, they got inverted, but I don’t like the “?” that appears at the beginning of the title of each single post. It looks like this:
? Post Title Blog Name

How can I take away the “?”?

How can I add a “|” to divide the post’s title from the blog’s name, that appears only for single post pages.

Thanks in advance