Believe it or not, one of my favorite things to do while in Vietnam was eating. Vietnamese food is delicious. You need to be open minded, though. Food presentation is very different from what we westerns are used to. You may also need to learn to eat with the chopsticks. It takes some time, but it is much easier than it looks. Ask a local if you cannot figure it out. Even if you do not succeed, I am sure you will have a good time trying.
By the way, if you are really open minded, go to one of the dog restaurants in Hue. Thit Cho (dog meat) is a local delicacy. I also heard of a cat restaurant. -- I skipped this one.