Acrylic paint is not waterproof. Do not display near water sources. Additionally do not display where it will receive direct sunlight.
Acrylic paintings are designed to be displayed as is. The sides of the canvas will be painted with a complimentary color that is in the painting.  A  "floating" frame designed for canvas paintings would be a separate purchase. The difference between a floating and traditional frame is that the canvas is placed into the frame from the front side instead of the back.

 Prices range from $15-$75 depending on the size of the canvas. I do not keep them in stock so to order one may delay delivery of your purchase by 1-2 weeks. If you are interested please use the contact feature to reach out to for me for additional information.
You can. You can purchase a traditional style (picture) frame, however, you must remove the glass as the acrylic paint will stick to the glass. Some canvas sizes are hard to find in a traditional picture frame. 

A traditional frame is designed for your "picture" to be loaded from the back. Therefore, the opening may not be deep enough for the canvas not to protrude out the back. The bulk of the canvases I use are 5/8" inch in depth. Flat canvas panels are just that...flat so they will easily fit into a traditional frame.

Shadowbox frames can be a viable choice based on the depth of the frame box.

I have used all of the above type of frames. I have located some at Michaels and Hobby Lobby in their clearance aisles. Thrift stores, Goodwill and flea markets are a good place to check as well.
While I hope my clients will always be thrilled and happy with their purchase life happens. A refund of the painting cost only will be granted once I have received the painting back and it is in good condition.