Hey! This is actually REALLY good for a first animation! It had a good joke that got a laugh out of me, and the expressions on the characters are really good!
Now, since this is your first animation, I suppose you're off the hook, for now, but here's some things you can improve on:
The brush size is a bit too big. Now, this is probably the smallest thing, but here's the thing, if the brush size is too big, it really doesn't look aesthetically pleasing.
Next, the coloring is a bit. . . off. Now, it's not terrible, but it looks like you used the default colors for some things. A trick I learned is, when you pick a default color, make it a bit darker. It'll look nicer that way.
Third, I noticed that you kept the camera on the woman while the man was talking, and put the camera back on the man at the end. That really came off as a, sort of, excuse for not lip syncing and animating poses. I'd recommend putting the camera on the man, and putting it on the woman to see her reaction to what the man is saying, and back at the man, and back at the woman again.
Lastly, the animation loops. This can be annoying to some, so you can either export the animation to Swivel and upload this as a video file, or add a replay button. This can easily be fixed, though.
All in all, great job! I look forward to what you make in the future, and I'm adding you to my favorites!