Seal Beach is only 15 - 20 mins. north from Huntington Beach going north on Pacific Coast Highway (PCH). I use to take my kids to the playground on Seal Beach for playgroup routinely and don't recall ever seeing any seals.
I agree with iceskatejen, Huntington Beach and Newport Beach are the two closes beaches plus they meet your requirements of a short trip and easy access. In November, neither beach will be crowded. It's usually quite cool then, thus the lack of crowds but you never know. During the first week of Feburary we had a few days that were in the 90's which is quite unusual. If you plan your trip on a Friday afternoon, there's a farmer's market/craft fair at the Pier Plaza in Huntington Beach. It's every Friday unless it rains or there is a special event that they're preparing for the weekend.