The top bit, called a fret board on a guitar
The Black Bit on the violin is called the fingerboard.
all over the fingerboard
The pitch of any violin string is changed depending on which spot on the fingerboard a finger is placed.
If you need them, put them on the fingerboard wherever you need your fingers to go.
They are called "frets", same with all stringed instuments.
If you mean frets to press the strings against - like the ones on the fingerboard of a guitar - there are no frets on a violin.
To play a violin effectively, you need to use a bow and your fingers to press the strings on the fingerboard in the correct positions to produce different notes and melodies.
It would be best to just buy a new set of strings and put them (all) on. While your at you it would be good to clean the fingerboard and stuff. Lemon or linseed(?) should do the trick for the fingerboard.
It's because the E string lies low at the very the right side of the bridge, so it has more tendency to hit the fingerboard when you strike it with your bow, especially if you have your violin tuned to a lower pitch. Another reason is that you might not be pressing the string hard enough onto the fingerboard with your fingertips.
The notes on a violin are produced by pressing the strings against the fingerboard with the fingers of the left hand and then bowing the strings with the right hand. The pitch of the note is determined by the length of the vibrating portion of the string.
The correct finger placement for playing the violin involves using the fingertips of the left hand to press down on the strings while keeping the fingers curved and close to the fingerboard.
You can get them at prowood fingerboard or flatface fingerboard.