There are many monologue collections in the library. To find them:
Should I use the word "play" in my search?
Sometimes searching keyword "play" is less helpful because you'll find lots of items with the word "play" or "plays" that don't have anything to do with theatre.
Need to find scenes with 2 people or look for specific aspects of a character?
Try North American Theatre Online or Twentieth Century North American Drama. You can search for scenes and limit to number of characters as well as gender, race, occupation, sexual orientation, etc.