There are useful things you should know before going to Bangkok:
1-The first thing you think about is to have your own map for everywhere in Bangkok and it will be better if it is detailed.
2-As you know Bangkok is a very hot City and you well get wet a lot because of the hot weather, you should drink a lot of water and always have a bottle of water with you, also your clothes better to be in cotton,that will make it dry easily.
3-To get enjoyed in Bangkok sightseeing try to not ride a car inside the city,to try the waterways, underground and Sky train.
4-Don’t forget to take with you a photocopy of your passport.
5-It is better for you to change money outside the airport .
6-Don’t eat many different foods, and it is better for you to begin with the fresh juices.