Logo not uploading

Hello

I am new to the forum and a beginner using wordpress. I have downloaded the formation theme and starting customising it through the admin panel and I have now advanced to the css files.

I am finding most information on the net but I am struggling with a simple logo upload. I should be able to upload my logo image through the customise theme option however everytime I upload my logo it will not appear?

Here is my website link http://mikeswebsite.co.nf

Any help would be appreciated.

Thank you

Mike