What is the importance of control points for my project?

Important if you want your project to be in correct scale and location. If only camera parameters are known or only inaccurate GPS locations then model is not in correct scale and location only approximate. 
Best program to create control points is to generate them in Contextcapture look under tools. Such control points(QR tags, April tags, Chili tags) can be detected automatically when doing aerotriangulation. Control points will need to be surveyed after placement or they should be placed on known locations.

If geolocation is not so important then correct scale and orientation can be achieved using user points(April tags) and measured using laser distance meter or ruler.

Important if you want your project to be in correct scale and location. If only camera parameters are known or only inaccurate GPS locations then model is not in correct scale and location only approximate. 
Best program to create control points is to generate them in Contextcapture look under tools. Such control points(QR tags, April tags, Chili tags) can be detected automatically when doing aerotriangulation. Control points will need to be surveyed after placement or they should be placed on known locations.

If geolocation is not so important then correct scale and orientation can be achieved using user points(April tags) and measured using laser distance meter or ruler.