Sanding to a real fine finish will only take more time.
When you put the finish on it will raise the grain,so you will have to sand it again.
Clean the wood with mineral spirits, That way you can see if there is any scratch's or swirl marks that need to be removed.
Mineral spirits will dry real fast and won't raise the grain.
Put your sanding sealer on than sand to the finish you want.
Apply your top coat.