If I want something made out of plastic...?

There are over 500 plastic fabricators firms in the city of Edmonton, Alberta alone. Any other city in North America that has oil and gas refineries is likely to have lots of fabricators. Which one you choose depends on the kind of product you require. It may be rolled in sheets like glass, molded, injected, cast or formed in a variety of other ways and combinations. Try posting a more detailed question.

I use to be a mold maker. There are not to many left in this country. China and other countries have tried to take this trade away from us. If you want something made from plastic it will cost you a lot of money. Unless you plan on selling your idea to the public, your idea is not cost effective. If you wanted to make something like a Christmas ornament, you want to look for a blow molder. Go to your local library and get the business directory and look up plastic injection molding.