Where can I get polyfoam, is it something joanns or michaels carries or will I need to order it online.

and also I plan to hand sew can't really afford a machine right now so is there any advice for keeping the pieces lined up I tried pinning them but it seems to wrinkle it a bit.

My son gets his foam from Joanns - it is green but if you cover it with fabric it doesn't matter.

You should be able to find poly foam at Joanns. You can also look in your local area for companies that cater to upholstery folks.

Pinning is the best way to keep your pieces even while sewing.  Since fabric has a stretch to it you have to often take care and patients while pinning and sewing so it won't wrinkle up on you. Don't worry, you'll get the hang of it with practice.

I never pin the fabric (while covering with "skin"), I just use a spray glue and glue the material to the foam leaving an excess to cut out and then stitch it up.
I have never had any problems with wrinkling doing it this way.

But I'm not sure if I understand your question well.

Joann's and Hobby Lobby both will have polyfoam, but Joann's in my area has the better price. Joann's is the only one between the two that is able to sell it by the yard. Hobby Lobby's is white, but its in specific sizes.

Micheal's here doesn't carry foam.

ah okay, yea I think i need like a bendable foam according to the pattern this is glued to the mouth plate

Ask in an upholstery store/warehouse too. They always hold polyfoam (in sheets or blocks).

Went to my local Hancock Fabric store, and found all sorts of foam goodies including a 14x14x14 foam cube.

Has anyone worked with the foam mattress covers they sell at WalMart and such?
A twin size one of those is $9.99 as opposed to $16.99 a yard or such at JoAnn's.

One side of them is flat and the other side is the egg carton type texture.

Has anyone worked with the foam mattress covers they sell at WalMart and such?
A twin size one of those is $9.99 as opposed to $16.99 a yard or such at JoAnn's.

One side of them is flat and the other side is the egg carton type texture.

I have and they are very economical for making prototypes or practice type puppets. I learned how to make several different puppets when I first started out in Puppetry using this foam. I found that the Dollar stores are a bit cheaper in price so you may want to check there.
I don't recommend using it for a puppet as a substitute for a higher quality  or to be sold. Always use quality foam when doing this.
I say try it ! once you get the puppet fever as we call it you will want better foam.

Billy D.