how to graph an equation on graph paper?

Make up some arbitrary values for x.  There is no limit to
how many to select.  The more you select the more accurate
your graph will be.  Of course if you know it is a 
straight line then you can get away with choosing only 2. 
But you must know that it is going to be a straight line 
to get away with selecting only 2.  Even when you know it
is going to be a straight line you should select at least 
3 values so that if you made an error on one of them, you 
would discover your error if they did not all three lie in 
a straight line.  But if the graph is a curve, then you 
must select more values. 

Substitute each value for x in the equation.

Solve the resulting equation for y

Each time you substitute an arbitrary number for x,
write a left parenthesis "(" followed by the x-value 
you substituted, followed by a comma "," followed by
the y-value you got when you solved for y, followed
by a right parenthesis ")".   This gives you an
ordered pair like this (8,-3) or (-7,2) or (4,6), or
(0,7), etc.

Then to plot a point put a dot at the point which is
vertically in line with (i.e., directly above or below
or on) the x-value on the x-axis, and also horizontally 
in line with (beside, i.e., directly right, left of,
or on) the y-value on the y-axis.

When you finish, draw a smooth curve or line dot-to-dot
starting from the point nearest the left side of the
paper and always moving away from the left hand side of
the paper and closer to the right-hand side of the
paper.   

Edwin