All kinds of people take cruises, all ages and from all walks of life. Singles, couples and families. Passengers can vary from ship to ship and cruise to cruise. Just ask your Travel Universal agent for advice on the best ship for you, your tastes and lifestyle. Cruising is ideal for people travelling alone, because it's so easy to meet other people.
Most ships also have single cabins as well as single rates for double staterooms.
In many cases, a cruise line will even find you an appropriate roommate to share a double if you ask them. Pack like you would for any resort. Generally, cruise vacations are casual by day, whether you're on the ship or ashore. In the evening, ships vary as to dress. Attire is dictated by occasion.