A great beginning! Oakland is full of wonderful things to do and look at. It just suffers from comparison with one of the greatest cities on Earth next door.

I would also add:
Take in a movie at the Grand Lake Theatre. The Grand Lake is usually a landmark for all of us (“I’ll meet you there…”) when we’re doing things in the lake district. But the theatre itself is divine. And great popcorn, too.

Have the spinach salad at DiBartolo’s, just half a block east from the Grand Lake Theatre, on Grand. Or, just have some coffee, sit outdoors on a sunny day, and people watch. Don’t be disdainful of the homeless guys working the corners; they’ve been there a long time, and know the neighborhood very well. They are for the most part non-aggressive.

Take a walk around the Lake. It’s 3.3 miles, and simply gorgeous, great exercise, very pleasant. If you’re into nature, see how many different species of birds there are (as Adar said). It’s a natural stopping point for birds going south….and it may be my imagination, but it seems many of them do not continue their journey south when they find out how pleasant Lake Merritt is.