To get to Charlie Brown's backyard, go left past the Flying Ace cafe. You need to complete the pumpkin patch first, then get the pen and invitation, before you can do the Snoopy and Charlie Brown scenes.
(see related question)
when you go to the snoopy food court [where you first enter] go to the left and that's Charlie Browns back yard
He is with Snoopy in his backyard, but only after you have gotten a pumpkin for Lucy, a bag for Pigpen, and a lemon sucker for Linus.
After you get the invitation and the pen, Charlie Brown and Snoopy are in his backyard, on the far left of the island. You will play a mini-game as Snoopy gathers some leaves in a very relaxed manner.
Charlie Brown's back yard is to the left of Main Street, with Snoopy's dog house at far left. You will not find anyone there until you have completed the pumpkin patch scene: roll the pumpkin to Lucy's house, go outside and give the bag to Pigpen, then give the sucker to Linus. Now you can play the Snoopy leaf game in the backyard.
Although you see him at the start of the island, and in the discussion with Linus about the Great Pumpkin, Charlie Brown does not appear in his backyard until you have completed the Pumpkin selection, Pumpkin rolling, and Pigpen parts of the game. 1) In the Pumpkin Patch, weigh the pumpkins and give the heaviest to Lucy 2) Roll the Pumpkin safely to Linus and Lucy's house 3) Take the bag from Linus and give it to Pigpen outside 4) Give the lemon sucker to Linus and pick up his Pen from the desk Now Charlie Brown and Snoopy will appear at the leaf pile in the backyard.
You go back to Charlie Brown's backyard. Charlie and Lucy will be there. You have to give them a pen. (Then pen is found on Linus' table after you give him his lemon-flavored sucker.)
The pumpkin patch is both the first and last point on the island quest. You go there initially to see Linus, and return a pumpkin to Linus and Lucy's house. From there you swap Linus's bag for a lemon sucker, and swap that for an invitation to the party, before going left into Charlie Brown's backyard.
in charlie browns back yard. you give him a pen you can get at lucys house. theyll leave the football on the ground to get costumes
The name of the island is Great Pumpkin Island. See the related question below.
Before you can do anything in Charlie Brown's backyard (left of Main Street houses), you have to go right to the Pumpkin Patch and perform two tasks: weigh a pumpkin for Lucy, then roll it back to her house safely. Take Linus's trick-or-treat bag and give it to Pigpen, then give the sucker to Linus, then pick up the pen. Now you can go left to where Charlie Brown and Snoopy are gathering leaves.
Charlie Brown is originally outside Linus and Lucy's house, and Lucy is inside. When you complete the pumpkin patch sequence, Charlie brown is with Snoopy in his backyard (left). When you finish collecting the leaves, and Linus jumps in them, follow him to mail his letter. After he does (with a delay to recover his blanket), Lucy and Charlie Brown are playing with the football in the yard.
Charlie Brown's backyard is in both of the places left of Main Street. But you don't find Snoopy there until you complete the first part of the island. Go to the pumpkin patch, pick out a pumpkin for Lucy, and roll it back to her house. Take the bag from Linus and go outside to give it to Pigpen, then go back in and give the lemon sucker to Linus. Once you have your invitation to the party, and the pen from the desk, you are ready to see Charlie Brown and Snoopy gathering leaves in the backyard.