Hi I'm a new in this programming thing and I have to create a car plantation management system yet I'm lost on how to out it together and if I should be using classes in my app

Unfortunately if you aren't sure if you should be using classes then this project is beyond your current skill set (sorry, but its true). Is this project an assignment for your study or an actual production piece of software? Either way I would suggest getting some .Net coding books out of the library. I find learning from a software textbook better than forums and online tutorials when you're starting from square one.