If my baby is fully taken care of to the point where she is fed, changed and cleaned and i put her down and shes just crying and crying and crying and i leave her there what could happen to my child?

You might actually get some rest. You do what you can to learn your kid, but crying is nonspecific. It can mean hunger/lonely/hurt/bored or even overstimulated. Doing all you can, then putting the kid down in a comfortable setting, soft music may be helpful, but it is okay to put on the headphones & take a break. Checking from a distance every 20-30 minutes will be enough. These kids grow up okay