It will certainly be a negative in your application. In addition, if you end a class with a D or F it could be grounds for any acceptance being rescinded.
You need to talk to your teacher and guidance counselor. Decide if you should stay in the class and, if so, how to improve your performance. If you can get a tutor that may help. Keep in mind that calculus builds on concepts so if you are lost in the class now it may be hard to recover.