Legend of the Continental Heroes - Arc 1

I was just living in modern Japan, when I realized I reincarnated in a early modern european styled world… no, it’s just like Europe, right dad? Anyway, I was reincarnated in a european fantasy. This is the great(?) tale of I, Joseph Wallace. Probably.
My second birthplace, the Silesia Kingdom, was in a precarious situation. The neighboring kingdoms military were pressuring the Silesia Kingdom until it collapses. I felt I should use my previous world’s knowledge to the fullest so I enrolled in a military academy… to become a cheat hero. Yep. I did not swing a sword in my previous life, I did not ride a horse in my previous life. Magic? What is that? I recalled “unnecessary information”… it’d be great if my story starts.