Sure, I'd be happy to help you plan your one-day itinerary in Munich!

Here's a suggested itinerary for you:

Morning: Start your day with a visit to Marienplatz, the central square of Munich. You can see the famous Glockenspiel, which chimes and reenacts two stories from the 16th century. You can also visit the New Town Hall, which is a beautiful neo-gothic building.

Afternoon: Next, head to the Viktualienmarkt, a large outdoor market where you can find fresh produce, flowers, and local delicacies. You can grab a quick lunch here, or just enjoy the atmosphere and people-watching.

Evening: In the evening, visit the Hofbräuhaus, one of the oldest beer halls in Munich. Here, you can enjoy traditional Bavarian food and beer, and soak up the lively atmosphere.

If you have more time, you can also visit the Englischer Garten, a large public park in Munich. You can rent a bike or just take a leisurely stroll through the park, and enjoy the beautiful scenery.

I hope this itinerary helps you plan your day in Munich! Let me know if you have any other questions or need more suggestions.