everyone has different sit bones and usually stock saddles suck. There are usually 3 width sizes and different size cut out or no cut outs. I HIGHLY HIGHLY recommend talking to the shop where you got your bike and see if they have a saddle demo program. If they don't, talk to another shop. Most cost $30-60 to buy into it and the cost goes into the purchase of which ever fits you. They should have a measure device, gel pad that you sit on and it will determine your width. From there you pick n choose cutout or not and shape/looks. You can blindly pick a saddle but they cost $80-200 a pop and if it doesn't fit, you have to sell at a loss and try another.
Yah and invest in good shorts/bibs. 1 good pair is better than 2-3 cheap ones.