Como is a beautiful city located in the Lombardy region of Italy, and there are plenty of things to see and do here. Here's an ideal itinerary for 3 days in Como:

Day 1:

• Start your day with a visit to the Como Cathedral, also known as the Duomo di Como. This stunning cathedral is one of the most important landmarks in the city and is a must-visit for anyone coming to Como.
• After visiting the cathedral, take a stroll through the historic center of Como. The city is full of charming streets and alleys, and there are plenty of shops and cafes to explore.
• For lunch, head to one of the many restaurants in the city center. Como is known for its delicious cuisine, so be sure to try some local specialties like risotto or polenta.
• In the afternoon, take a boat tour of Lake Como. The lake is one of the most beautiful in Italy, and there are plenty of tour operators offering boat tours that will take you around the lake and show you some of the most beautiful sights.
• End your day with a visit to the Tempio Voltiano, a museum dedicated to the life and work of Alessandro Volta, the inventor of the electric battery.

Day 2:

• Start your day with a visit to the Villa Olmo, a beautiful neoclassical villa located on the shores of Lake Como. The villa is surrounded by beautiful gardens and offers stunning views of the lake.
• After visiting the villa, take a funicular up to the top of Brunate, a small town located on a hill overlooking Como. The funicular ride is a fun experience in itself, and the views from the top are absolutely breathtaking.
• For lunch, head back down to Como and try some more local cuisine. There are plenty of restaurants to choose from, so be sure to ask for recommendations.
• In the afternoon, visit the Como-Brunate funicular museum, which tells the story of the funicular and its importance to the city.
• End your day with a visit to the Como Archaeological Museum, which houses a collection of artifacts from the Roman era.

Day 3:

• Start your day with a visit to the Villa del Balbianello, a beautiful villa located on a promontory overlooking Lake Como. The villa is surrounded by beautiful gardens and offers stunning views of the lake.
• After visiting the villa, take a boat tour of the lake and visit some of the other beautiful towns and villages that are located on its shores, such as Bellagio or Varenna.
• For lunch, try some more local cuisine at one of the many restaurants in the towns and villages around the lake.
• In the afternoon, visit the Como Silk Museum, which tells the story of the silk industry in Como and its importance to the city.
• End your day with a visit to the Como Volta Lighthouse, which offers stunning views of the lake and the surrounding mountains.

I hope this itinerary helps you plan your trip to Como!