Avoid embarrassing yourself and find out in advance whether you are expected to bring a gift when you visit someone’s house or whether you’re supposed to take your shoes off before you enter, as is common all across Europe, Russia, and Asia. If you are expected to bring a gift, you should learn what is acceptable or what is not. In many countries it is not acceptable to bring a bottle of wine for the host, as it implies you don’t think you’ll be satisfied with their choice of drink.
If you plan on driving in your new city, be sure to learn about the driving habits and laws, and whether a law is actually a law or whether it is just a suggestion on the road. In some countries you may notice 5 lanes of traffic routinely squeezed into 3 lanes, or the car behind you flashing their lights (they aren’t warning of a cop, they’re telling you you’re going too slow and you need to get out of their way). Knowing beforehand what will happen behind the wheel will help you avoid an accident.
A healthy appreciation of food is a commonality the world over. Learn about what you should and should not eat or drink in your new country. For example, Western stomachs can’t stomach the water in many underdeveloped countries. Also important to a positive culinary experience is knowledge of the manners and norms about food and eating. Is it polite to ask for seconds? In a culture where “no, thank you” really means “yes”, how do you politely decline something? When eating at a restaurant, how do you ask for the check?
Women in some countries may dress more conservatively than you may be used to and in some countries less so. Be aware of the differences and plan accordingly. In some cultures neither men nor women wear shorts, in others women can wear whatever they like as long as they cover their heads in church. Such rules about dress can also vary within the country: what may be OK in the big, bustling capital city would be cause for alarm in a smaller, rural village.
As a teacher overseas, you don’t need to know the local language to do your job, but a basic knowledge of few key phrases will go a long way in helping you settle comfortably into your new life. Once again, a good guidebook and the many resources on the internet will go far in acquainting you with important words and phrases.