You get the pen in the BLUE house. Then you walk back to Charlie Brown [ be right next to him!] and click on the little brown pack in the corner of your screen, find the pen, and click USE. HOPE THIS WAS HELPFUL! :-)
By snoopy's doghouse
You give it to Charlie Brown, and he will sign Lucy's contract
It is in Linus's house on the desk.
you go to linus and lucys house after or while you give linus a lemon flavored lollipop and its will be on the desk.
When you go to the far left later in the game, Charlie Brown needs to sign a document and he needs you to get a pen for him to do so. See poptropicasecrets.com
you pick up the ball and use it near snoophie the dog,you will find snoophie glasses there are on the tree
you go to the girl with the blue dress A.K.A Lucy and she will say to the boy with the yellow shirt with the black stripe A.K.A Charlie Brown and she will talk him into signing a piece of paper but Lucy and Charlie don't have a pen therefore you have to press use when ur next to Charlie Brown and there you go :)
To get the pen for Charlie Brown in Poptropica, you need to retrieve the pen from the map in Great Pumpkin Island. First, find Lucy's psychiatric booth and talk to her. She will ask you to find Linus, who is sitting outside the school. Linus will give you the map with the pen on it.
you go to the pumpkin patch or the party i think
once you give Linus his blanket (can be found in the leaf pile that he jumped in) then go back to Charlie Brown's yard and give the pen to Charlie (the pen is on Linus' desk) and then they will leave and forget their ball. then you have to throw the ball for snoopy and then watch out for the red baron.
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.)
There are two different footballs in Poptropica.If you are talking about the Great Pumpkin Island's quest item football, you need to get the pen from the desk in Linus and Lucy's house after Linus leaves, and he will leave after you give him the lemon sucker which you get from Pigpen for finding his trick-or-treat bag. After getting the pen, head left to Charlie Brown's backyard, where Charlie Brown and Lucy are practicing placekicks. Give Charlie Brown the pen, and when their scene is done, they will leave the football. You can pick up this football and then use it to get Snoopy's aviator cap and goggles from the tree above his doghouse.Or, if you are talking about the wearable football that you have seen random characters wearing, such as in the beginnings of Early Poptropica and Shark Tooth Island, it is not available. It is uncustomizable and can not be bought anywhere (unfortunately). Sorry!Hope these help!