[QGIS] CREATING CONTOUR IN QGIS 

This video explains how to draw contour in QGIS and how to annotate the contour.
The contour interval used in this video is 1 m.
You can change color of contour lines.
Qgis version used is 3.4.2. but you can use other versions as well.
Import X,Y,Z from excel in CSV format
Install Contour plugin
Draw contour in qgis