You can do it without coding...
Customizer > Site Identity > Logo Image > Select Image...
Once you upload your logo, it will use your logo as a link instead of site title.
You can also check out these photos logo ideas http://highendbeautyretouching.com/blog/advertising/photography-logo-ideas.html In due time this article was useful to me!
Thanks Josi B, sorry by delay. I still couldn't solve it. When I upload my logo at site identity panel like you said, nothing changes. My logo isn't clickable.
It seems an issue with your wordpress settings, I tested but didn't face the issue like you