I've visited Kawaguchiko many times, and it never gets old. You have about 50% chance of seeing Mt. Fuji with higher chance during early morning and in winter.
Fuji Visibility Forecast

Below are some of my top recommendations for how to enjoy your time:

1. Take a Boat Ride on the Lake

• You can take a ride on small swan boats or large samurai-themed ships, both offering a unique perspective of Mt. Fuji and the lake.

2. Hike to Arakurayama and/or Tenjosan (Kachi Kachi Yama)

• These are the two popular hikes that offer breathtaking, unobstructed views of Mt. Fuji.

• Tenjosan has cable car access if you don't want to hike up or down. At the top, you’ll also find spots to grab a snack and soak in the panorama.

3. Go for a Lakeside Walk or Bike Ride

• The path around the lake is perfect for a leisurely stroll or cycling.

• Here's how to rent a bike: https://matcha-jp.com/en/12246

4. Enjoy Local Food and Cafes

• Try Kawaguchiko’s famous houtou noodles—a hearty dish perfect after a day of exploring. There are also cozy lakeside cafes where you can relax with a cup of coffee or tea.

5. Enjoy Local Food and Cafes

• Try Kawaguchiko’s famous houtou noodles—a hearty dish perfect after a day of exploring. There are also cozy lakeside cafes where you can relax with a cup of coffee or tea.