Fishing is all about patience and taking your time. If you quickly become uncomfortable in your fishing vessel, your patience will run thin. So, comfortable seating may seem like a luxury, but any serious fishers who have been out for more than a few hours know that it's very important.
If your canoe only came with a bare bench, you should consider installing a cushioned backed seat. Some prefer to kneel, however. If you'd like that option, you should install adhesive kneeling pads. Carpet is a nice addition for those who like to kneel, as well, and it will help soundproof your canoe.
With these tips, and a little of your own creativity, you can see how easy it is to turn your canoe into a bona fide fishing vessel.