You can find this first step in MANY Acting books, bios, YouTubes videos, etc. - what are five adjectives that people use to define you? You are to ask people who know you well, know you generally, and don't know you at all. These adjectives need to be based on how people view you. It's not solely based on looks.
Keep things to always consider - what is your age/age range, gender, race, and sometimes even your nationality. These are important because they connect YOUR lived experience to the characters you could potentaily play.
Peronality. Look at characteristics when searching for audition pieces, but also when you are preparint for you auditions. These are wonderful hints and clues to help you make clear, strong choices.
What's your Actor Type using this as you guide?