The Cove Beach is beautiful and is part of Scripps Park which is a beautiful park on a bluff just above the ocean. You can walk south from there to the Children's Pool area to see the seals on the beach and walk out along the sea wall. Continue walking south you will pass Whale View Point and the Museum of Contemporary Art.
All of this is walkable (assuming you don'd mind some hills), including Prospect Street which is a couple blocks up from the coast.
The Cove, Children's Pool and the tide pools are some of the nicer, natural attractions.
Girard Ave is one of the top shopping streets as is Prospect Ave.
Many great places to eat, some have views, some don't, it just depends on the experience you are looking for and type of food.
Pirok - Will you have a car to get around?
Pirok974, since you will not have a car, it will be much harder for you to see all the places the previous posters have mentioned. As I already answered in your PM, from where you are staying you will have to take public transportation.
How was your time in La Jolla? We arrived last night and tho the weather is a bit cooler than we hoped for, we are really enjoying our time in this beautiful town. Last night we enjoyed an excellent meal at George's California Modern. Our table had an oceanview and the food was of the highest quality. Our sever was very attentive and recommended several Mexican restaurants to us when we go to Chula Vista later today. :)
syrahgirl, I recall on one of your other responses that you are looking to go to Tacos el Gordo, just be aware that it is a hole-in-the-wall place. More taco-shop than restaurant. You order at a counter & they have a few tables inside, otherwise you eat it to-go. I would not necessarily make a trip out of your way to Chula Vista to eat at Tacos el Gordo (they're delicious, but it is not a very touristy location so unless you have another reason to be down there, we can recommend other top notch taco shops for you to try).
syrahgirl, The chef at this restaurant has been written up in the NY Times Restaurant section for his place in Tijuana. This one is in Bonita(right next to Chula Vista) and he's supposed to have one opening in Little Italy in San Diego. I don't know if it is open yet.