Linked Clothing Banner

Hello All

Bit of help if I can, I have searched but couldn’t find a direct answer.

I have set up a website for a Firework Event we are running in April, this features History of the event, details etc etc.

We have a member of our Firework Forum who is running specific clothing for the event, hoodies with the logo on etc.

I would like to place a banner that is seen on each page that is linked to the site you can get the clothing from.

Using the Striking theme and there is a black box above the footer – be good to insert it in here, how could I go about adding this?

Thank you for your help in advance.

Kind Regards

Mark