I bought yoga pants because they are typically a little wider at the bottom and only come part way down your shin. They were really comfortable and easy to put on. I didn't have to wear a gown in the hospital except for the day I went into surgery. Once I was back in my room I changed, so I could be comfortable.
Good luck and keep posting! Feel free to ask even the silliest questions if it makes you feel better - we've been there.