As it's your first short film, the problems with the script and acting are to be expected. Good acting is a very hard thing to do on a low budget, as I've mentioned countless times before to others, so don't worry too much about getting it spot on for your first couple of films.
The main idea from the first few films you shoot is to get a grasp of what works and what doesn't. Certain choices when it comes to shots, for example, and continuity between them all through both the visual and auditory elements of the film.
As the others have mentioned, audio is a problem. Throughout there were volume problems, sure, but you'll learn to avoid them as time goes on. What I would like to point out though is that when you have one scene, whether it's based directly before another or after, is still an individual scene, so try and keep everything continuous within it. I'm not sure I explained that properly... The main example I'm looking at is the scene where he's tying his hair up and in the bathroom. I'm assuming you're working with one camera, but the problem I'm noticing is that between the shots the sound changes. What you'll want to do instead is record yourself doing those actions, including getting the sound, and then rerecord the scene from the different angles, not worrying so much about the audio that time other than keeping in sync with your last shot. Working with a single microphone makes this difficult, but basically what recording the audio all in one go does is it keeps the audience connected to the scene even when the shots change, and that's a very, very important thing that people tend to overlook.
Best of luck to your future projects!