Going SOBO with little to no experience, am I stupid?

I'll be attempting a thru hike sobo this summer 2025. Been preparing and researching for almost 2 years and really ramped up my fitness this year. BUT I am a native Floridian (flat land) and have barely seen mountains let alone hiked in them. The reason for sobo is due to timing constraints.

Am I going to die starting out with the hardest and most rockiest parts of the trail? I'm actually getting pretty scared I'm making a big mistake. How can I make sure I'm safe and prepared? I'm also hiking it with my spouse.