Challenges using language

When speaking to from a different culture or community than my own, it can be challenging for me to second-guess what I am saying to not offend them. I might think that it's no big deal when making a simple non-verbal gesture, but that person could take it as disrespectful. For example, in my neighborhood at home, I frequently go to the corner gas station where an Arab man works. One day as I had my hands full with items I shook his hand with my left hand. He later told me that in his country that was disrespectful. It is challenging to know what is considered rude in all countries.