the 10-20 and the 50mm f/1.8 would be a good combo. I doubt you will need a longer lens then 50mm will work for indoor portraits. 10mm is _very_ wide I'd call it a specialty lens. Even 20 is wide. But if you learn to use the 10-20 (You need to get very close to some subjects. you will have photos that people like. Beginners tend to stand back and use a longer lens. Ths makes for a "flat" image and up close and wide style is more engaging and involves the vewer in the image but it's a style you have to work at learning. The 18-55 "kit lens" gives you the easyst to use range
Best advice is Do Not Wait. Shoot 500 frames before you leave. Try to find a place where there are people, buildings and public spaces. (It should not be hard to find) close to where you live and learn to shot those subjects close to home as that is what you will e doing in KH. It takes some experiance to learn how to use the distortion inherent in a 10-20mm lens to your advantage
Suggestion: if you have a 10mm and are shooting a building. Don't point the camera up, Keep the camera level and then when you get home crop off the bottom of the frame. You will get a rectalinear renderring. Loads of other things like that learn and try withan extream wide angle lens
