What type of file is it?
Pic, document
If its a pic right click it and click print. Duh!
If its a document open it word or whatever, go to file then print.
That depends on a lot of things. What device did you use to access email? How did you access your email through that device (browser, app (if applicable))? Where was the attachment saved? How do you connect to your printer?
You may create a Windows Central account to provide us more information.