A frontend developer works between a designer on one end and a backend developer on the other, translating the design into code and plugging the data from the back-end into the right spots.
Front-end web development is NOT design (you won't be playing around in Photoshop or anything), but a front-end developer does apply the work of designers to the web page by translating their well-designed layouts into real code. The front-end developer stands between the designer on one end and the back-end developer on the other, translating the design into code and plugging the data from the back-end developer into the right spots. They must also handle all the possible interactions that the user may need to make with the page.
On the front end, you will need to be highly conscious of who your user is and how they will be interacting with your web page, because you are building their gateway to your page or product. This may mean gaining a strong understanding of accessibility and things like responsive development down the line, but first you need to build up your toolkit and pick up the fundamentals of the front-end languages.
In the following lessons, you'll get a healthy understanding of each of the three front-end languages. To get warmed up, we'll start at the high level.
Look through these now and then use them to test yourself after doing the assignment:
Bookmark DevDocs.io. Read the "Welcome" message. Massive API documentation collection that even works offline. Essential collection of reference material for everything covered and more. (Maintained by FreeCodeCamp)
This section contains helpful links to other content. It isn't required, so consider it supplemental for if you need to dive deeper into something.
This video is another great introduction to how the various front-end technologies interact.