Using the :GetMass of a model(I think) how would I make it so that it would be able to set the amount of force(BodyForce) it would take to 'float' the model 2 studs off the ground based on its "Mass"
You can take a look at this wiki page about gravity in roblox. It mostly explains how you'd get the object to float.
For keeping it at 2 studs, you could use a BodyPosition, set it's position's y to 2 (or whatever is 2 studs above your ground) and then set the x and z of the maxForce to 0 so those aren't affected, just the y.
This would need lots off math, but basically put: you would make the Y velocity the mass (I think) + the distance of 2 studs.