As you make a symmetrical airfoil thicker, in which direction does the lift force increase? I am working on a project and just need to understand one concept that I cannot find an answer to anywhere and hoping you could answer for me.

The project I'm working on is with airfoils and the main on NACA 63-021. In short, from what I have read as the foil get taller/thicker it creates more lift and can handle higher angles of attack as well. 

My question to you is: if a foil like this which is symmetrical top and bottom foil shape, what direction of lift is increasing as the foil shape gets thicker? is the lift seen as forward motion lift/thurst?

You help on this would be greatly appreciated!
Lift is defined as the vector component of the total aerodynamic force perpendicular to the freestream velocity vector. Wikipedia about lift

By definition lift can not contribute to thrust or drag, so the direction is fixed.

The sense of the lift vector is opposite to the flow deflection caused by the angle of attack, so the lift increases in that sense.

For your project you might be interested in looking at the lift/drag profile, rather than just at lift.