Find a local saltwater club, aquarium or LFS.
The key to success in this hobby, as mentioned, is to research and choose appropriate animals for the tank you have. And that does not seem to be the case here. You can succeed if you stay within your limits, but without that, it will be a very frustrating battle.
If you really do not want to do this anymore, then I would encourage you to trade the fish in as soon as possible. It is not fair to the fish to be unwanted, as it leads to poor water quality and impacts health. So definitely try not to let that happen