That web guy

Hi everyone! I apologize for what is probably a dumb question. I have two Google Tag codes that I need to have running on every page. Is there a specific way I should do this? There are no fields for it in the template. My first though was just echoing the tags with PHP on a file that runs everywhere. Is that possible? And if so what file would it be best to add it to? I really appreciate your help, I have never used ProcessWire before.