Since you are guaranteed to make mistakes out there, why not learn vicariously from other thru-hikers in order to limit your learning curve.
Hiking For Beginners: 11 Essential Tips
The Most Common Hiking Mistakes and How to Avoid Them
Extreme Hiking: America's Best Hard Dayhikes - The Big Outside
The World's Most Dangerous Hikes
Thru-Hiking Appalachian Trail Conservancy
7 Reasons Why Women Make Great Backpacking Leaders On the Trail — She Dreams Of Alpine
20 Mistakes I Made on my Appalachian Trail Thru-Hike (learn from them)
7 Tips for Thru Hiking the Appalachian Trail — She Dreams Of Alpine
5 Mistakes Most Beginner Hikers Make (How to Avoid Them)
Thru-Hiking Appalachian Trail Conservancy