Need workout question

ok, I’m 14 turning 15, 5’9’’ about 125 lbs. I throw high 60’s-low 70’s. I pitch almost completely sidearm. I need a workout that I can do during the offseason to get stronger(I’m really skinny and to increase velocity)
-plz post a link or just write out what a typical week would look like

I’ve never lifted before…but I have done medicine ball and resistance band stuff

thanks!

go to www.gatoradeperformance.stack.com

sign up on there and select baseball off-season strength for your goal. I have been doing this workout for 3 weeks and i just threw yesterday and i feel much stronger and feel like i don’t have to put as much effort into throwing the same velocity as i used to.