Some machines are noisier than others. When I bought my Bernina 1230 many (many!) years ago, one of my first priorities was a quiet machine. My Bernina just hums and purrs. At the time, I worked in a dealership and most of the machines were what I would consider noisy.
Noise varies for individuals. There are some sound frequencies that bother me that my husband cannot even hear.
Given the information you have provided, about the only options you have are (1) take the machine back to the shop where you bought it and see if they think it is noisy. If at all possible, I would ask to sew on the same model they have in the shop and compare it to yours -- sewing on it in the shop. It may be that the shop has some ambient noise that masks the sound that bothers you. Option (2) is to sell your machine and purchase a different brand. Most dealerships will not take returns on machines, but you may be able to "trade up".
For a machine in this price range, my first choice is always to check on Amazon to see if there is one that Amazon both sells and fulfills. When dealing with Amazon exclusively (instead of a 3rd party seller fulfilled by Amazon), I know I can return something I don't like easily, paying only return shipping (if there's nothing wrong with it and I simply changed my mind. If there's something wrong with the item, I don't even have to pay for return shipping).