What types of workouts do I need to focus on to prepare myself for pre ranger school?

Whole body workouts. You don’t need to lift nor would you want to. Push-ups get the majority of guys. Ranger school really isn’t physically demanding but more about physical and mental endurance. Which ore ranger would you go to? Ft Campbell has an awesome one and RTAC down in Benning is good also.
If you would like a routine then I would check out military athelete. That’s the one I went with.

SGT Robert Cupp I don't know how accurate this is, but this is what I found. looks solid to me though
http://www.passranger.com/p/90-day-ranger-prep-pt-plan.html