Greetings, Leah. Thank you for stopping by the Disney Parks Moms Panel! How exciting you and your son will be taking your first BIG trip to the Disneyland Resort.
To answer your questions:
1) There are exciting attractions at both Disneyland and California Adventure your preschooler will love. When my children were younger, we all enjoyed Disney Junior - Live on Stage! It was so fun watching them sing and dance along with their favorite Disney Junior characters. Cars Land and "a bug's land" are great places in California Adventure for preschoolers as well. Hop on over to Disneyland and you'll again find numerous attractions suitable for preschoolers, with my family's favorites being "it's a small world", Many Adventures of Winnie the Pooh, and Peter Pan's Flight.
2) There are
Lost Children facilities at both parks in case you and your son separate. Before each day at the parks, my husband and I both take photos on our phones of our kids and note their outfits. My daughter is older and has her own cell phone now, but we used to write numbers on their forearms with Sharpies in case we separate. Also, we let them know it is okay to ask for help from cast members who wear badges.
3) You will have opportunities to see some Star Wars characters at Star Wars Launch Bay in Tomorrowland. While there, your preschooler can learn to duel with a lightsaber in the Jedi Training experience. Currently, Big Hero 6 characters do not have meet-and-greets at the parks. Character experiences are subject to change, so check the
Disneyland website for the most updated schedule.
I wish you a wonderful trip to the Happiest Place on Earth with your son. Please come back to visit me here on the panel if you have more questions.
~Kiki