Hey there!
To plot the inequality y≥-6 on the coordinate plane, keep in mind that whenever you have y set equal to a constant, your graph will be a horizontal line. Therefore, your graph would be a solid (not dashed since your sign is greater than or equal to) horizontal line passing through (0,-6). Then you would shade the portion over the line to signify that the values of y must be greater than or equal to -6.
The graph below shows y≥-6: