<a href="clickable link"><img src="URL of logo image" alt=""></a>

I don't know where you would have to put this code without seeing the theme code, but if you know a little about PHP and themes, just put this code wherever the theme calls for the logo.

its easy, go to all the pages you have in the setting below the editor box, go to the header settings and enable clickable header and you can also set a custom url for it.

let me know if you got it fixed !!