Have the travel agent secure your seat assignment and boarding pass when booking your flight. Luggage Your suitcase is your single most important travel item. It should be lightweight, practical, and preferably not brand new. You should be able to carry it loaded with no great difficulty. Hard is best if you'll check your luggage, soft is best if you'll carry it on the aircraft.
Most airlines allow one carry-on bag, sometimes two if the other is a purse, camera, or briefcase.
The average storage area under seats is 9 x 14 x 22 inches. If you have a large suitcase and expect to be walking alot at the airport, then a set of wheels on the suitcase or a luggage stand on wheels makes sense. But sometimes wheels can be awkward, inconvenient, and just not useful. They don't go up stairs, over curbs, or onto buses easily. You may want to take two small bags, with shoulder straps, rather than one larger one if you think you'll have to carry them a lot.