Keep calm, love math.
It is really just distribution. You just have to do it twice. Double the distribution, double the fun!
The picture above represents the multiplication of (2x + 1)(x - 3). When using this method you need to make sure the sign of each term is correct. Note the minus 3 is a negative 3!
Khan Academy - Multiplying Binomials
Learn about the mysterious FOIL method that used to be commonplace in every math class. Notice the differences between my video and Khan's video. The FOIL method has limitations because it only works when you are multiplying two binomials. As you will see later on in the unit it makes more sense to think about distribution when multiplying to polynomials together because the idea of distribution works for all examples.