There are many things that could be addressed to improve accuracy with any given person's setup. The tune of the bow, the size of your arrows, the point weight you are using, etc....
For instance, just the other day I was switching point weights from 100 to 75 grains on one of the sets of arrows I was shooting. My groups instantly tightened up because I made that "adjustment". What that was telling me is that the arrows were too weakly spined for the setup I was using.

If you are just starting then I would take it one step at a time and rule out each variable before making any major changes. Start with a basic tuneup for your bow. Are your cams properly timed? Is your tiller set correctly? Do you have any fletching clearance issues? If all of that seems fine then I would move onto your arrows and try some different sizes and point weights. Eventually you will find a combination that increases accuracy for your bow.

...that is, assuming, it isn't your shooting form that is the problem.