Choosing a destination where getting around alone is simple

For my first longer solo trip I care less about ticking off landmarks than being able to move around without constant logistical puzzles. Walkable areas, straightforward public transport, easy food options and a calm place to return to at night matter a lot. I'm comfortable navigating, just not eager to rent a car alone. When you evaluate a destination for solo travel, what practical signals tell you daily life there will be easy rather than exhausting?