In string theory ? any explanation on what cause things to move?

Answer 1

So, what causes things to move still obey the original Newtonian laws of physics.

What String Theory does is it tags on 7 extra dimensions to explain things that we CAN'T with current theory, such as dark energy, missing higgs boson, and the unification of relativity and quantum mechanics.

But as far as why things move, F=ma will still do the trick.