And what is your point....that the first to fire was to blame?
Then, the Union troops at Ft. Barrancas take that honor.... a full three months before Sumter....January 8, 1861.
But if you want to focus on Ft. Sumter, the first shot was fired there by the Union Ship Harriet Lane, by Union Lieutenant Tompkins.
He was a part of the Lincoln Cabal military.
Union troops at Ft. Barrancas fired warning shots to deter thugs who were advancing upon the fort.
The Harriet Lane fired a warning shot against a ship closing on her at night while flying no colors.
The rebels fired upon Fort Sumter as an overt act of war against their own country.