Munich, Germany - My first solo trip to Europe. Munich is such an amazing city and I quickly fell in love with it. Extremely clean, pedestrian friendly, and easy to get around. The city has a ton of spirt with classic architecture. After WW2 leveled the city, Munich made the decision to rebuild brick for brick the same way it was before the war. They used old pictures to reconstruct the exterior of the major buildings.
Viktualienmarkt has all your grocery needs for a nice DIY lunch. Take a leisurely stroll through the English Gardens with ein maß bier and check out the surfers in the river! If you're staying near the train station, I highly recommend Augustiner-Keller bier Garten. It's more expensive than your average bier hall but it makes up for it with the atmosphere. Also a 15 minute walk over the train tracks will take you to Augustiner-Brau with full service beer hall at almost half the cost.
Heidelberg Germany - Visiting Stephan after 10 years was such a blast. I got to meet his daughter and we spoke English/German together. The town of Heidelberg is pretty famous when it comes to tourists becase it's one of the only cities that escaped destruction during WW2. There's also a nearby US military base outside the city.
A university town, it's packed full of students rushing to class down the narrow pedestrian walkways. Bring a rain coat however because it always rains in Heidelberg.
Hike up to the castle and walk down by the riverside. Hit up a cafe and take in the scenery. There are plenty of restaurants to stumble upon through Alt Stadt and every street has a Cafe. This isn't a city to rush through. Take your time.