[subject] + have + [object] + [past participle]
[subject] + get + [object] + [past participle]
Have something done means that you arrange for another person to do something for you. You don't do it yourself. The object (the thing) comes before the past participle.
The order is have + object + past participle. If you put the participle before the object, it becomes the present perfect, with a different meaning.
Have changes for the tense. The past participle stays the same.
In everyday speech, get can replace have. The meaning is the same, and it is a little less formal.
The same pattern can describe something bad that someone else did to you.