Hi, i'm pretty young (I don't want to share my age.) and i'm bisexual. I don't know how to come out to my parents, and i don't feel like they are going to take me seriously. I almost am saddened that i have to hide who i really am. Any advise?
You do not have to hide who you are. It is always best, generally, in life to be honest. That being said, we also can't control how others respond to our honesty. That isn't important. We much live according to our own truths.
Give your parents the chance to understand you. It may take them a little time to wrap their heads around who you really are, but once they come around, it would be very worth it. For both you and your parents.
If you can find an lgbt support group in your area that would be helpful for you.
Be strong, come out, and have confidence in yourself, and love yourself, no matter what their response.