I can't know what your teacher wants you to find out or what they want you to put in the 'chart'. You can't find the 'answer' to an equation like this one unless you've been given more information but you can find out lots of useful things about the graph.
For instance, for your equation, y=2x+4 , you can see that if you graphed this equation you would have a line.
Also, the gradient (slope of the line) is found by looking at the number before the 'x' term, i.e. in this case the gradient is 2.
Also, the y-intercept (where the graph goes through the y-axis) is at 4.
Also, if you want to find out where the graph hits the x-axis (i.e. when y=0), then
0 = 2x + 4
-4 = 2x + 4 - 4
-4 = 2x
-4/2 = 2x/2
-2 = x => So the line goes through the x-axis at -2.
You now have enough information to draw a rough sketch of this equation.