They're both "three-chord specials." That is, if you're playing in C, your chords will be C, F and G7 (or G if you prefer).

These are good songs to practice learning when to change chords. Just try playing each one, starting on a C chord. When the C chord stops sounding right, try G7. If that doesn't do it, try F instead.

If you play it enough, it will become automatic to select the right chord. After that, you will be able to find your own chords on many other 3-chord songs.

Good luck!