Help with custom css font to apply to item titles in shop

Hello! I am trying to add some custom fonts and tweak sizes on my store. I would like the font to be 'the-stockholm-font'. 

the site is www.millyfletcher.com/prints

I have circled the bits I'd like added. Any help welcome! Thank you 

Thank you so much for the speedy reply! Worked a treat. Do you know how to tweak the size of the header? Or actually if it's possible to remove? Maybe if you could provide both options I can see which looks better. Thank you!