Language misunderstandings can lead to awkward interactions. You might use a wrong word or phrase that has a completely different meaning in their language. Say, there was a word in the local language that sounded like a rude word in English, and I accidentally said it. The host family's reaction was really strange at first, and then I realized my mistake. Another thing is about sharing the bathroom. In some cultures, people are more private about bathroom use, and adjusting to sharing it with the whole family can be a bit of an ordeal.
Differences in social norms can create awkward situations. For instance, in my host family's culture, it was normal to greet everyone with a big hug and a kiss on the cheek, but I was not used to such close physical contact with people I didn't know well. It made me feel really uncomfortable at first. And then there are issues like gift - giving. I gave a gift that was considered inappropriate in their culture, not knowing the proper protocol. It was a bit embarrassing, but we managed to laugh it off later as I learned more about their customs.
One common awkwardness is differences in meal times and eating habits. For example, if you're used to having dinner early and your host family eats very late. Also, when it comes to food preferences. You might not like something they serve but don't want to be rude. I remember I didn't like a certain type of cheese my host family loved, and it was hard to decline it without seeming ungrateful.