This matrix A, are the columns linearly independent? Do you know how to find out? I'll tell you if you don't.

Assuming they are linearly independent, what is the null space of A?

What is the span of the three columns, i.e., how can you describe the set of vectors that can be expressed as linear combinations of those three?

I could be wrong, but I get the impression you don't understand what the terms "column space" and "null space" mean. If you don't, find out.