Never, ever put anything valuable in checked luggage. Either tuck it in your inside pockets or carry on bag, or send it registered mail ahead of time, especially if you will arrive there before your package.
Get a light, rolling case small enough to fit under the seat, and double check what you are taking with you. You do NOT need every item of clothing in your closet. Most experienced world travelers (of which I'm not, I listen to those who are) take very few things with them for a 2 week stay. You can hand wash underthings/socks/hose, and even most real fabric clothing. A tiny travel iron with special electrical connections will work nicely. Don't forget that nearly every country in the world would be glad to sell you any clothing you need or want. Think of taking a pretty caftan for a house coat/lounging robe. Some of these are lovely and warm in over cooled hotels.
Wear comfortable shoes, and if you can find them, disposable socks to wear till you get through security, then toss them.
Personally, due to a previously broken ankle, I choose to wear lace up cowboy ropers that are not easy to remove, but with all the walking in a large airport they really pay off in comfort. Then I use the small (less than 3 ounces) bottle of hand sanitizer after removing/putting boots back on.
Get a hanging bag that you pull over your neck and tuck inside your shirt and your important papers, money, credit cards, etc will remain with YOU, and not thieves. Carry a large bag that has your medications, make up, spare clothing and a smaller wallet with a little cash in it. Make sure any males with you put their wallets in their front pockets, even though the neck hanger would be better, but we know how stubborn men are. My DIL used to be a travel agent, and said lots of men had their pockets picked, but the women and few men who wore the neck bags on tours never did lose much at all.
After passing through security you can buy one or several bottles of water/soda/juice and take it onboard with you. Take a snack if you don't feel like buying over priced sandwiches on a less than day long ride.
In spite of all this, you CAN have fun on vacations. Ship home all you buy that would be awkward to carry with you on board a plane or ship.