first check the time signature to make sure you've got the rhythm right. what note has the beat? a sixteenth note is half of an eighth, which is half of a quarter, which is half of a half note, which is half of a whole note. to read a time signature, check the top number--that's how many beats per measure. the bottom number is what kind of note gets the beat. for example, in 4/4, there are 16 sixteenth notes per measure.
now make sure you're playing it right. use a short, small amount of bow.
lastly, i suggest you look into getting a real violin teacher if you haven't already.