Hello Austin,
I have just read your post and here is information that you need:
If you want to stay here not more than 180 days, then you don't need any visas. And even if you are going to stay here for more than that, you are a US citizen and they don't need invitation letters as stated in this article. So, if you really are a US citizen, there is nothing to worry about.
Best regards,
Yuriy