The 22lr suggestion is good but if you plan on running a bolt action do yourself a favor and find an CZ or Tikka 22lr bolt action. I've got a CZ 452 as a trainer and it feels like a real rifle. Then I go to the 270win after this. It just helps.

Another good thing to do is shouldering and bolt manipulation and dry fire practice. This costs nothing and it build tremendous muscle memory and form. I do this a decent amount and then I go and practice offhand field shooting.