It is impossible to answer this question directly, because there are hundreds of cultures from around the world, and every culture has its own customs. Nobody is an expert on all of these cultures, so it is ok to be ignorant of what is culturally respectful in a specific culture.
If in doubt, the best thing to do is ask whether your behaviour is appropriate and be willing to realise that people are different. If you relax and understand that your way is not the only way, you’re off to a great start.
If you accidentally make a mistake, simply apologise and learn from your mistake. Nobody is perfect!