Not bad for practice, though, there are a few things here that bothered me: namely the backgrounds, consistency and music.
The choices for backgrounds in this are awfully inconsistent throughout; some look like they were done by you in flash, and others look like photos you found off the internet. I'd say the set of stairs the girl bikes down are by far the most out of place; those stairs are huge and the rendering of your character was tiny in comparison. I'd suggest more consistency on those BGs in the future.
In terms of the drawings and animation, I felt it was pretty good overall. Seems like the main character wasn't always on model the whole time though. especially around :17 compared to say :24.
As for the music, well, Kabalevsky's 12 Comedian's Gallop feels far too energetic and exciting of a song for the content here. Nothing in this short was that exciting to need such music. Also, along with the music, the ending here kind of seemed like a rip from the short animation: Fumiko's Confession (which also used the exact same music as this).
Anyway, im not writing this to be a jerk; just giving some constructive criticism, especially given that this is supposed to be practice.