You might want to make a table of values of powers of 2.
You could begin by letting x = 0, 1, 2, ... , obtaining the following points:
(0,1), (1,2), (2,4), (3,8), ...
and then let x = -1, -2, -3, ... , obtaining (-1, 1/2), (-2, 1/4), (-3, 1/8), and so on.
Plot these points. Then draw a nice, smooth curve through them. Note that y = 2^x increases as x increases.