If this is a course in chemistry and you have to take further courses related to chemistry or biochemistry. Then knowing how atoms are put together and operate makes it easier to understand the more advanced information. I teach HS chemistry and my kids ask that same question while we are doing the basic stuff and I am drilling it into their heads. Then when we do the hard stuff, they see how it all fits together. I even have some who have called me from college and said that my class really helped them out.
Good luck and if you do need help, just let me know. But yes, the Kahn Academy is a good resource as well. If you have an ipod or such, there are apps for his work.