hope that this can help me fix my van, its hard to drive to work.

The vehicle will shift, but hard shift and found every 3rd time I start from a stop it will not shift unless I turn the engine off and start it right back up and then I'm good for 2 more times it needs to shift up. Anybody have any ideas what could be the problem? I have been told a number of things it could be, not going to just start spending money until I know what is the problem.