Short answers, pulled from the story.
The first experimental pioneer assault unit was founded by Major Calsow in the spring of 1915, following orders from the Ministry of War. Hauptmann Willy Rohr took command on the 8th of September 1915 and developed the unit's defining tactics and equipment, leading to its redesignation as Assault Battalion Rohr on the 1st of April 1916.
German stormtroopers used infiltration tactics that combined a short artillery bombardment with poison gas to neutralize enemy lines, followed by small dispersed squads bypassing strongpoints and targeting enemy headquarters and artillery. Junior leaders were given authority to make on-the-spot decisions rather than following centralized plans.
Germany launched Operation Michael on the 21st of March 1918, using the new assault tactics. Four successive offensives followed, breaking the trench stalemate for the first time in four years, though a decisive breakthrough was never achieved before the Allies launched their Hundred Days Offensive in July 1918.
Rohr's stormtroopers carried the shorter Karabiner 98a rifle, the 9mm Lange Pistole 08 with a 32-round drum magazine, grenade bags, trench knives, and clubs. They wore the Stahlhelm steel helmet and lighter footwear, with uniforms reinforced with leather patches on the knees and elbows for crawling.
The offensive stalled for several reasons: the initial attack hit the most strongly held British section of the front, leading units were never rotated out and became exhausted, the terrain of rivers, towns, forests, and canals slowed the advance, and the 1918 influenza epidemic weakened the ranks.
According to scholars Robert G. L. Waite and Klaus Theweleit, the stormtrooper experience contributed to the paramilitary culture of the Weimar Republic, spreading the breakdown of officer-enlisted barriers, fierce unit loyalty, and a brutalization from trench warfare into every major party's paramilitary wing. The Nazi Party directly adopted the name Sturmabteilung from the original German assault units.