You can calculate the potential of onepointin the force field, relative to another point, by integrating along any path from the second point to the first. If the force is conservative, the path doesn't matter so you can take the simplest path, say, three lines parallel to the axes. That is

integrate from (0,0,0) to (x,0,0), then from (x,0,0) to (x,y,0), then from (x,y,0) to (x,y,z). That is the potential of any point relative to (0,0,0). The potential relative to some other point would be that plus a constant. It would be really good idea to check that this is a conservative force field so that ithasa potential.