Solo paddling, although very popular, is much more dangerous than group paddling. Don't paddle solo until you are a very competent paddler, and even then, be aware that your margin of safety is limited when you have no access to quick assistance. Many beginner paddlers paddle solo because they don't know other kayakers. This is where the clubs and outfitters like Atlantic Kayak Tours can be invaluable. Clubs offer many good programs for people with boats. Indeed, some culbs own a few boats for members to use.
As a group paddler you have responsibilities. You should not go on programs which are beyond your skill level, you should have the right equipment, and you should be in shape for the program. While out on the trip, stay with the group and understand that the group moves only as fast as its slowest paddler. If the group is moving too slowly for you, paddle a zig-zag course or practice your support and turning strokes as you wait for the rear of the group. Most groups have lead and sweep boats: stay between them for your safety. The lead paddler is choosing the route that the group will follow. Those at the front of the group should always be within shouting distance of the paddlers at the rear. Notice that this means the group should cluster more tightly when conditions make people more difficult to hear. When crossing boat channels, the group must stay very close together. Accordingly, slower paddlers should push, and faster paddlers should slow down. Group paddling is great fun when everyone helps one another. If you see someone having difficulty, try to help. Watch the leader and learn for another time. Good leaders have reasons for almost everything they do. Ask questions, they'll be glad to explain.