For this equation you simply have to graph it.
First, you have to remember that these equations follow a formula: y=mx+b. m is the slope of you line and b is the y-intercept.
Next, you need to graph it. First, graph your b, in this case 2. You would go up 2 on you graph (graph (0,2)). Then, you would graph your slope which is 3.
Now, remember that slope equals y/x, so think of the number 3 being like 3/1. You would start at (0,2) and go up 3 points in the graph, then over 1 point (graph where you end up). You repeat that from each new point you make until you have enough points to create a straight line.
Hope this helps a bit,