Fonts and Typography not working

I think I may have broken my website. I’m trying to change font but I’ve been going round in circles for hours. If I have no font plugins installed the ‘typography’ option in the ‘customise’ menu disappears. So I can’t edit fonts at all. If I activate ‘easy google fonts’ the typography options re-appear but don’t actually do anything (for example, if I select the colour red for heading 3 it does;t change to red). I’ve tried installing Googel APIs and other hieroglyphics but I’m not convinced I’ve put them in the correct place.