It is easy to travel abroad with a little one, so try not to panic!
First thing I would say is prebook your seats on the plane for the bulkhead... for a little one you get a fold down cot or bouncer chair for the bulkhead for no extra cot - plus you get loads more leg room
Take your sunblock, sun hats etc... UV swim suit. Try to get a little bottle with a spray top, that you can fill up with water to mist cool water in his face.
Have a bottle for him to suck on for take off and landing to help his little ears.
Don't fill your suitcases with loads of nappies etc... You can buy all that there. If you are doing a fly/drive trip.. once you are settled and have your car, take a trip to the Walmart and you can buy all his nappies/wipes etc. You will also be able to get a wee pop-up sun tent from there too for under $10 I would imagine.
Remember as well... if you are traveling with an infant... at the airport, you get to board the plane before anyone else... usually along with the first class passengers, so that you can get in and all your stuff in the over head locker without other people pushing and getting in your way.
Hope that helps, and have a fab trip!