Problem : What are the two ways to form a plane?

The first way is with three noncolinear points. All three lie in the plane that is formed. The second way is with a line and a point in that line. The line must be perpendicular to the desired plane, and the point in the line must be in the desired plane as well.

Problem : Is it possible to form a plane with just two points?

Yes, but only one of the points will lie in the plane. The two points must be used to form a line. This line must be set perpendicular to the desired plane, and the plane must contain one of the two points given.

Problem : What is the difference between coplanar and noncoplanar points?

Coplanar means that the points in question all lie in one plane. Noncoplanar means that the points in question do not all lie in one plane.