I got my violin from a local music store a year ago, and now I'm noticing scratches on my violin. There are some scratches that are pretty deep. I don't know what caused that to happen. (The wood my violin is made of is very thin) There are no holes (except for the f-holes of course) And, the area between my bridge and under my fingerboard (where the rosin falls) has a light white on it. When you scratch it with your nail, some of it falls off but it's not rosin. If it helps to know when my violin was made, it was made in 2009 and is a half size. I have a silk case that I put it in. I'm wondering if I have to polish it at the store or maybe just let it be??
The light white very likely is resin dust. Any serious amount of "polishing" will work it into the varnish rather than help. Instead lightly wiping it off after playing with a soft cloth should suffice until the violin actually gets to visit a luthier for some reason or other.
One of the most common scratches I see on my rental violins that get returned is from students storing their shoulder rest on the face of the instrument in the case. Even though the pad side is facing down, movement in the case can cause the edges of the feet joints to contact the face and scratch it.
In some violins the scratching is caused by the bow not being secured and moving around in the case and contacting the face also.
The white powder on the face between the bridge and fingerboard is most likely rosin dust, but new instruments may have residual polishing paste under and around the neck joint and under the fingerboard. The final polishing on instruments is done with large polishing wheels and occasionally polish residue remains in the hard to reach places. Usually the residual polish can be removed with a soft cloth, or if necessary some liquid violin polish and a cloth.