Symbols displaying incorrectly in Chrome, Firefox, & IE, but not Safari

I was advised to post this here, so hopefully this is the right place to post this!

Up until yesterday afternoon, my site (centerbear.org) was displaying correctly. However, after I downloaded (and subsequently deleted) a plugin that was supposed to make an easy version of the site for mobile users (which just didn’t look like even the same site), the symbols on my site no longer look right. In particular, the magnifying glass next to the search bar, the down arrow (and really any other “<“, “>”, or “^” or the down version) in my main head menu, and the little home button that displays on all non-home pages underneath the menu bar (which now displays as something like a Chinese character on Chrome and a box with 4 letters in it on Firefox).

When I am in the dashboard and customize my theme, everything shows up correctly, but when viewing the site live, that’s where the problems lie. I tested it on Safari, and there are no issues there.

I have cleared my cache and tried it on multiple computers, but it remains unsolved.

I’m currently running version 4.1 of WordPress with the Tempera theme (though it’s been customized).

Could someone please help me fix this? I’m also new to WordPress and I did not set up any .php pages, nor do I know where to find them, so I’d love some help there too if that’s where the problem lies! (Sorry I’m such a newbie!)

Thanks in advance!