So I bought a small bonsai from a small shop recently and everything went well, but now it's beginning to look dull and I have no idea if I'm watering it too much or too little. I'm also very unsure of which kind of species it is.

It looks like it might be a redwood... if you are keeping it where the picture was taken, it is dying because it is inside.

Oh.. So it needs to be outside.. Is it possible that It can be placed near a window?

Trees really aren't suited to indoor life...especially those that need seasonal changes.
There are many other factors that might be leading to problems, besides being inside. I could be wrong about the redwood.

have a look here:

www.bonsaiempire.com/tree-species/redwood


www.bonsaiempire.com/tree-species/bonsai-identification

im with tubaboy looks like a redwood.

and most likely looks unhealthy because its indoors. i have a few, redwoods need sun but make sure they are protected from intense midday heat as mine were unhappy with intense heat and bounced right back after placing in a position were it receives dappled shade.

Alright guys. I'll try place the redwood in front of my window. To see if it improves, I live on a apartment. So a balcony is all I have for an outside.

I hope you mean in front of the window, outside on the balcony. A windowpane indoors is still indoors.