Hey fishinstrument.

You are young and can go far. First of all, I don't know how hard it would be for you to get a hold of, but it seems that maybe your instrument is too big for you. Don't worry though, you will eventually grow into it.

First of all you need to tune the instrument properly before practicing and performing every time. It's very hard to play in-tune if the violin is not tuned.

You should also work on long sustained notes. Practice for now just drawing the bow from one end to the other while making your own observations as to what works for a good sound and what does not. More pressure, less pressure, closer to the bridge, further from the bridge, faster bow, slower bow. Just experiment and get familiar with the action and reaction of your instrument.

Good luck and keep on posting.