What to say in this situation?
So today I talked a few sentences to someone in German (In real life!) and it didn't go too well.
He told me "Nett dich kennenzulernen" and I said "dir auch" which I think I used the wrong case, and he even corrected me (Sie auch) :D
Then a bit later he said "Auf wiedersehen. Viel Spaß"
What am I supposed to say back? I just said "Ja, dann" which seemed like the best thing to say but it felt weird. Feedback?
If he said "nett DICH kennenzulernen (nice to meet you)" the right answer could be "danke gleichfalls" which is something like "thank you, likewise" No need to become formal (using "Sie") if the other one used "Du/dich". If he said "nett Sie kennenzulernen" the formal "sie" is recommended. You could have said "finde ich auch" to imply that you're agreeing with him.
For goodbye you could have said "Auf Wiedersehen und Danke" (goodbye to you, too and thank you (for him wishing you to have fun)
"Ja dann" seems a bit weird, but may be used between good friends and younger people.
Btw, no need to feel embarrassed. First time I spoke to a real life American I didn't know what to say, either.
I'm just going to react to the way he corrected you. If he actually said "dich" to you and then corrected you that you should have said "Sie auch" then he felt he can talk to you informally and expected you to talk to him formally. One of the few ways I can imagine this happening is that you are very young and he was middle aged or older gentleman .. is that right? In these situations you should never adress him du/dich/dir, unless he asks you to first.
I bet he corrected you just for your information and didn't think anything bad about it. Since you're a learner it's normal you will make mistakes. Great you had a chance to speak to a German speaker, I had a similar chance a month ago and enjoyed it very much :-) Happy learning.