There is a lot of walking over archaeological sites so comfortable walking shoes a must.
I also took a pair of walking sandals, and a pair of smart sandals for evening ( you probably won't need those ! )
You will need to have shoulders and legs covered for religious sites.
The food is great and plenty of vegetarian options.
If you let JY office know you are vegetarian then the guide will have a note of that and always arrange veggie meals for you.
I don't like to stay off airport so I always stay at sofitel ( expensive ) or yotel ( cheap ) so I can mosey round airport shops and restaurants in the evening.