If you're not driving to Pasadena, you can take the Metro Gold Line which stops at several stations in Pasadena, including Memorial Park, Fillmore, Del Mar, and Lake. The fare is $1.75 per ride, and trains run every 15 minutes on weekdays. However, to reach some destinations from the Metro station, you might need to take a shuttle, taxi or rideshare service.
If you have more time, consider visiting the Pasadena Museum of California Art or the Rose Bowl Stadium, where the Rose Bowl Game is annually held every January 1st. Alternatively, if you have less time, you can skip one of the destinations on this itinerary, but make sure to visit at least 2 places that interest you. To avoid the heat and crowds, start your day early and bring sunscreen, hat, comfortable walking shoes, and a bottle of water.