可以在类中使用.val吗？

I am fairly new to programming and am stuck on something that I thought would be easy! I am creating a car with the make, model, and year. I am finding the value of what the user types into the input text box and printing it on the head of the page. I am able to find the value with an ID but when I try to make it a class, it does not allow me to print it out. Can anyone shed some light on this? Thank you!!I am fairly new to programming and am stuck on