How do I get a recommendation letter?

Is there like a paper or form that my teacher needs to fill out? Are recommendation letters different depending on the college? Or can I just ask my teacher to write me a letter and they’ll just know what to do? Also I know there’s different types: one where I can see what my teacher wrote and one where I can’t. How do colleges know which is which? Sorry if this is a stupid question but my family isn’t from America so I don’t really have anyone to ask