I hope you now have a clearer understanding of the difference between the roles of web developers and web designers. Keep in mind that both have essential roles, and the web would not exist without one or the other. I can tell you that from my experience nothing will come easier then the rest. Working full-time as a front-end developer, and interacting regularly with both designers and back-end developers, has shown me that all of the roles we just discussed have their own quirks in one way or another. Just keep in mind that focusing on one language at first is the best way to get yourself started. Once you get motivated and take the first step, the rest will be less of a challenge.