Hello, just came across this. Hopefully you were able to get to Sesame Place and meet the characters, but figured I'd provide an answer for anyone else interested.
We were at Sesame Place San Diego last week and had a great time. The character interactions were a lot of fun. To meet characters, check the Sesame Place app and look for the Shows section. They'll have various characters with times listed.
These are the times the characters will start their meet n greets. They seemed to last about 15-20 minutes, but a lot of times, when one was done another would come along a few minutes later.
The typical meeting place is around the corner from the carousel. We saw characters both inside the corner building and across the street in the open. The building is the iconic building from the show with the steps and 123 address. Oscar is on the corner, go around him and you'll see the M n G door. We saw Elmo and Cookie Monster together, which was fun, then Abby by herself across the street.
Also, Big Bird has a story time at his nest. He's not reading, but he does interact with the reader and the story. After the story, the kids can line up for a picture with Big Bird. He has wires to help with the wings, so he doesn't really do hugs or anything.
Also, they have an afternoon parade that has many characters available that you can take pictures of. Towards the end, the parade stops and the characters sing and dance in the streets. They also interact with the kids, wakes, dancing near them, things like that but not much touching or hugs. The kids may be able to get a fist bump or high five though if the characters can see them trying to do one of those. If you want to be near Elmo when the parade stops, the sidewalk area between the 2 trees to the left of the green building in my picture above would be a great spot or right across the street.
There's also a stage show twice a day which we unfortunately missed out on, so I'm not entirely sure who all is there.
Most important thing though is checking the app on the actual day of your visit as Characters and Times can and will change. I checked a few days before our visit and Julia and Zoe were listed, but the day of, neither of them were available, but Abby was, which my daughter was extremely happy about.