Plot the point (-1,1)

The first coordinate -1 is the x-coordinate

Find -1 on the x-axis and draw a vertical line through it,
like this in green

 

The second coordinate 1 is the y-coordinate

Find 1 on the y-axis and draw a horizontal line through it,
like this in red:

 

Notice where the green and red lines cross.  Draw a dot there.

 

Erase the green and red lines and label the point (-1,1):

 

Notice that is directly above -1 on the x axis and right beside 1 on the
y-axis.

Edwin