Wikia

Non-Members are Penguin's that do not pay a subscribed membership or had their membership expire on Club Penguin.

What Non-Members Can Do

Buy colors, flags, pins and backgrounds.
Obtain free items given away at parties, become an EPF Agent, Ninjas and tour guides.
- Mostly head items.
Wear pins, found hidden on the Island and flags from the Penguin Style.
Buy up to two Puffles.
- Two Blue Puffles, Two Red Puffles, or one of each color.
Waddle around anywhere in Club Penguin, excluding "Member-only" rooms (such as Member Party rooms, the Underwater Room, Fire Dojo and the Water Dojo).
Chat with other penguins.
Unlock items using a book or toy code.
Play games but with less levels.
Earn stamps, excluding Member stamps.
Meet Famous Penguins.
Unlock items or puffles with a code.
Decorate their Igloos with 6 free furniture items.

Upgrade their Igloo or buy furniture.
Buy any color Puffle except red or blue.(However, they can get any color of Puffles if they have a toy code.)
Cannot participate in certain events at parties.
Can't open their igloos to guests or host parties.
Obtain stamps that require membership.
Buy most clothes or objects.
Obtain Member-only pins like the Moss Key Pin.
Buy or obtain Member backgrounds like the Coral Reef Background.
Play certain games (like Card Jitsu Fire) and certain levels of games like Catchin Waves.
Enter members-only rooms.

Non-Members seem to be usually seen waddling around wearing Card-Jitsu Belts, the New Player Red Baseball Hat and the Amulet.
Members are often criticized by Non-Members. Non-Members sometimes even protest online, and along with protesting, they can sometimes even boycott Club Penguin's Limited Edition Penguins and the other toys by not buying them. This case keeps getting more severe over time.
Non-Members are complaining that Disney's taking over has affected their rights to play all of the levels in games and earn items other than Head Items.
If your membership has expired, and you still have a members-only puffle, your puffles stay with you.
At the Marvel Super Hero Takeover, there was a catalog where Non-Members could buy items with coins for the first time.