I am not sure if you have traveled to a developing country before, but do be aware that the poverty is striking in Thailand, particularly Bangkok. Emotionally, you will probably be shocked by a few things, unless they've cleaned things up since the last time I was there.
You might want to prepare yourself mentally for what to do when approached by beggars (not our version of "homeless people"; these are people with 1 or 2 limbs missing, and often blind/deaf etc). Also, even though you are married and will be at your husband's side most of the time, women AND men of various ages will approach him to ask if he'd like to partake of their "services." Learn to ignore them steadfastly or say "No thank you" very firmly, over and over again.
And, with trying Thai food, especially right off the street (often the best way, but also most dangerous)... be aware of traveler's diarrhea, especially the first 3 days you are there. Even if you are careful with your drinking water (ALWAYS bottled, and check the top to make sure it's the original one and hasn't been refilled), your stomach may not be used to what's in the food. Take something along to help with that.
If you are going to be in the "jungle" (I assume you mean Chiang Rai, where the elephant training center is), be sure to wear long pants/shirtsleeves to protect against mosquitoes. Malaria and dengue fever, among other things, are still problems in those areas.
And speaking of long pants... make sure that both you and your husband have something long/covering to wear into the temples, even in Bangkok. Last I remember, you cannot wear shorts into a temple (unless they've totally relaxed for foreigners, which would be a shame). You also must take off your shoes, so be prepared for that.
And never, ever point your feet at anything... certainly not any person, but even at a market or something, DO NOT use your feet to indicate an item you'd like to buy, etc. That is just as rude as giving someone the middle finger, and they will probably jack up your price significantly or swear at you profusely in Thai, or both.
Learn how to say hello and "wai" (bow, with hands pressed together) in Thai, because that will get you a long way with most people. A few more phrases memorized would do a world of good.
/more than two cents from your resident half-Thai TFP'er
