Munich Tips:

Drink all the beer. Duh.
Munich is super diverse, far more than most European cities. Take it in, talk to the locals, get to know different cultures.

Head to the English Gardens to see people surfing the river, locals soaking in the sun in the summer (some naked, heads up!), and the beer garden in the center
Augustiner Keller: Hugeeee beer garden, really delicious beer, and an isolated atmosphere away from the crowds and heat of summer. Probably my favorite!
Go to Dachau. The concentration camp is jarring but it's a must. It's an easy train and bus ride combo from Munich, plan to spend at least half a day.
Lowenbrau Brewery: Another great brewery, slightly off the beaten path which is a nice reprieve
Spend a day at Lake Starnberg. A quick train ride takes you to the lake, then jump on the boat where you can get on and off at the different little lakeside villages. My favorite was Seeshaupt, don't miss the tiny little beer garden on the lake!

Hofbrauhaus Brewery: Touristy but a must!
Marienplatz: The main square of the city, home to the gorgeous New Town Hall, Old Town Hall, and the Column of St. Mary
Karlspatz: The old city gate and fountain are a nice place to sit in the evenings and relax. Pro Tip: the gelato place to left of the gate has delicious gelato that makes your time sitting by the fountain fantastic
Schlobpark Nymphenburg Palace and Gardens: Classic European Palace!

Stroll along the river, but beware of the naked sunbathers!
Explore the Glockenbachviertel Neighborhood. A more local area, home to lots of restaurants and a cozier vibe
Vitalmarkt: A pretty large market filled with all kinds of food!
The Beer and Oktoberfest Museum: Don't get your hopes up, this is super cheesy and ridiculous, BUT I still recommend it. I learned a lot about Oktoberfest and the beer culture in Bavaria. It is extremely small so don't plan on it taking too long. No worries, that means more time for drinking the beer instead of learning about it!
Paulaner Brewery: One of the Munich locations for Paulaner is right around the corner from the Beer and Oktoberfest Museum. There are several throughout the city so take a seat and drink up
Der Pschorta Brewery: Right off the Vitalkmarkt, another traditional German beer garden