Add a table to your expression list to start plotting points.
Next, fill in the table cells:
Note that you can have multiple scatter-plot columns in the same table:
If a table heading is a function, we'll fill in all of the values for you. One special case: a column heading can reference any of the previous column headings in your table. For example, if you have an "x" column, a "y" column, and an "x+y" column, we'll fill in the x+y column based on the first two columns:
You can long-hold the icon next to a scatterplot to see various options, including the ability to connect the points, to hide the points, to drag the points, and change the color:
Now that you have a scatterplot, how about finding a line of best fit? Learn more about regressions in Desmos.