Come on back for questions now that you're over the getting started hump.
Here's a short backgrounder on a helpful way to think about R
One of the hard things to get used to in R is the concept that everything is an object that has properties. Some objects have properties that allow them to operate on other objects to produce new objects. Those are functions.
Think of R as school algebra writ large: f(x) = y, where the objects are f, a function, x, an object (and there may be several) termed the argument and y is an object termed a value, which can be as simple as a single number (aka an atomic vector) or a very packed object with a multitude of data and labels.
And, because functions are also objects, they can be arguments to other functions, like the old g(f(x)) = y. (Trivia, this is called being a first class object.)
Although there are function objects in R that operate like control statements in imperative/procedural language, they are best used "under the hood." As it presents to users interactively, R is a functional programming language. Instead of saying
take this, take that, do this, then do that, then if the result is this one thing, do this other thing, but if not do something else and give me the answer
in the style of most common programming languages, R allows the user to say
use this function to take this argument and turn it into the value I want for a result
