I'm currently using a .png file for my logo however this is slightly blurred, no matter how much I edit it.
I now have an SVG of my logo but i'm struggling with being able to actually use this as my logo.
I have looked in a lot of the files under the edit code section but having absolutely no luck!
I would assume you need to go to your header.liquid file. Find the code where it displays the img for your logo and replace that <img> with your SVG.
But again do you really want to do that? Just make your png logo very high ppi.