An overarching principle to reflect on before initiating a strength program is that to be a good athlete at any sport you must first be a well-functioning human. You need to be able to squat, hip hinge, press, pull, sprint, jump, etc. Any program that leaves a gaping hole and calls itself "sport specific" is not "human-general". I have coached 4 professional baseball athletes, and about 2 dozen high schoolers that earned collegiate scholarships ranging from JuCo's to D1 schools, and 2 that were drafted from HS. That's not a lot compared to some more seasoned S&C coaches, but I think they would agree your first goal should be to build yourself steadily into a durable, powerful, and graceful young fella so that when you're called upon to use your baseball skills and strategies you can really stand out.
My athletes all started with Goblet Squats, 2H swings, and overhead press, and TRX row variant, along with basic A-marches before sprint work. As they progressed and gained better motor control they learned the barbell lifts. Most days involved some version of Dan john's Litvinovs (usually Ecc Overspeed Swings + 10m sprints). We had no injuries. And all my young guys were STRONGLY encouraged to devour ample amounts of whole milk and bacon Daily.
Google "eric cressey" and you find a wealth of baseball "specific" training info. best of luck to you, Rough Rider.
