Here are a few ideas for a 11 year old's birthday

Have a theme party: Choose a theme that the birthday child loves, such as their favorite movie or TV show, and plan activities and decorations around that theme.

Have a backyard or park picnic: Pack a lunch and some games and head to a local park or backyard for an outdoor celebration.

Go on a scavenger hunt: Create a list of items or challenges for the birthday child and their friends to complete around the neighborhood or park.

Have a movie night: Rent a projector and screen and set up a cozy movie-watching setup in the backyard or living room.

Go on a fun outing: Take the birthday child and their friends to a trampoline park, laser tag, or an indoor climbing gym for some active fun.

Have a craft party: Plan a craft project for the birthday child and their friends to do together, such as painting, building with clay, or making their own jewelry.

Have a cooking party: Choose a recipe or two and invite the birthday child and their friends to help prepare a meal or snack.

Have a game night: Gather a selection of board games, card games, and other indoor games for the birthday child and their friends to enjoy.

Go on a nature hike: Explore a local nature trail and have a picnic along the way.

Have a sleepover: Invite the birthday child's friends over for a sleepover party, complete with games, movies, and snacks.