Fonts:
Typography:
https://www.monotype.com/font-pairing#/playground?fontPair1=Milo+Pro&fontPair2=Pona+Book
Color theory:
https://www.canva.com/colors/color-wheel
Mockups:
https://www.freepik.com/search?format=search&last_filter=query&last_value=&query=&type=mockup
https://www.pixeden.com/free-graphics
Icons:
Stock images:
https://www.pexels.com/search/free
Inspiration: