USA, California-Need Recommendations: Cool Weather Mountain Town with Cute Cafés & Easy Strolls

Any recommendations for a cool-weather mountain town within 4–6 hours of San Diego for a relaxing trip? Ideally somewhere with cute cafés, a small walkable town center, lake/mountain views, and not much hiking (pregnant-friendly).

I stay in San Diego and bored of beaches. Im interested to visit mountains/ lakes/ cute cafes but cant travel more than 5 hours as Im due in a few months.