Although we did have a car, we tried to get in our 10,000 steps a day while we were visiting Santa Monica. From our hotel, we were able to walk to the Pacific Park Beach and the Santa Monica Pier. These are some of the major tourist attractions in the area and there were people everywhere enjoying the beautiful sunny weather. We were not there for the rides as we still had an upcoming day at Universal Studios planned but it is free to walk on the pier and take in the expansive views..
There are many restaurants along Ocean Ave to get a quick bite or a beverage should you need refreshment while sightseeing in this area. In addition to enjoying the crashing waves on the sand and the people watching on the pier, you can find artwork and some historical monuments, like a cannon, along the walking trails above the beach as you move towards Palisades Park.
If shopping is more your speed, then head to the Third Street Promenade where you will find three blocks of stores and cafés with street performers and landscaped dinosaur art fountains.
It sits next to an upscale retail center called Santa Monica Place, this is an area of downtown where you can find whatever you need from simple basics to luxury goods. Even if you don't want to shop, the people watching is good here, too.