I'm travel through Germany for a month. Anything recommendations?

I'll be in Amsterdam April 30th - May 7 then spend one week in each of the following cities:

Hamburg, Berlin, Stuttgart, Munich. Then travel south either through Switzerland or Austria!

It's my first time through Germany, so any friendly tips or places I should check out? That'd be much appreciated!

If anyone would like to meet up, that'd be awesome too

Germany is one of my fav countries out of 3 by far
1. Germany 2. sweden 3. south africa

8 years ago, I was backpacker and travelled alone to the Europe
and I had alot good memories about Germany
I met alot cool people in Germany, but idk if you would have crush there lol although, there are alot of german girls on Hey-ai but you never see many of them like to communicate or join-in forum section. maybe culture difference or lanuage matters idk
the best advices from me, 1, take train ride, 2. go south. 3. don't reject any homemade sandwhiches offered by the nice strangers. 3. if you met seniors or some german who are nice but couldn't speak well english then keep smiling to them, few of them may guide you to the places where you are looking for. 4. Don't reject any missonary girls who come to you and talk to you, beacuse you might meet angel of god.

thats all, I hoped you made a good trip in that country, although my respond is too late now