Shorts and t-shirt is fine during the day. For evenings in the dining room, look HERE
Internet has a basic fee of 75 cents per minute but they have package deals for various numbers of minutes which reduces the per-minute cost. For example I think it is $55 for a 100 minute package. You establish an onboard internet account which will have a user ID and password. Shipboard internet isn't blazing fast and can be offline at times since they rely on a satellite connection. The minutes go by fast. Just don't forget to log out. It is good to remember that if the logout screen can't be found to just type 188.8.131.52 in the browser and that will log you out.