It has been an eventful and often bumpy ride for Ryan Walters in his second season at the helm. And, it’s not over yet. There are three games to go for Purdue (1-8 overall; 0-6 Big Ten) beginning with this Saturday’s visit from Penn State (8-1; 5-1) at 3:30 p.m. ET on CBS. What has Walters learned along the 2024 path? “The most important things I’ve learned?” said Walters. “Man, I mean, there’s a lot. A lot I’ve learned. We could be sitting up here all day talking about it.” Among the possible talking points: • Firing OC Graham Harrell after four games • Naming analyst Jason Simmons play-calle…