Animated Mouth over Existing Photo

[Really lost here...brand new to Animate]...

What I need to do (for a basic comedy video) is to either place an animated cartoon mouth onto an existing photograph of a face...or animate the face photo's existing mouth.  Let's go w/ the 1st option (as low budget effects can also be funny).  [AND...I'm not sure if 'Animate' is the app I need].

So...right off the bat in Animate, I'm off to a bad start.  I opened the app; and imported a still photo onto the stage, but I'm not seeing any animated mouth sets anywhere, so as to be able to place a cartoon mouth over the existing mouth in the photo.  Are there additional files I need to download to 'Animate'...or do I need to use 'Character Animator'...or do I need to use plain 'ol 'Photoshop' or 'Illustrator'; & accomplish my animation in one of those.

Any help would be appreciated...I've watched various tutorials, but none are relative to what I need to do...thanx,

mw4man