Short answers, pulled from the story.
The Russian Provisional Government began on the 2nd of March 1917 following the abdication of Tsar Nicholas II. Mikhail Rodzianko headed the Provisional Committee of the State Duma in the Tauride Palace and suspended the Fourth State Duma to take formal state power.
Prince Georgy Lvov became the first Prime Minister of the new administration formed by the Provisional Committee. He led the government until his resignation on the 21st of July 1917 when Alexander Kerensky took over as Prime Minister.
The June Offensive started on the 16th of June but lasted only three days before soldiers mutinied and killed their commanding officers instead of fighting. This failure resulted in thousands of deaths and great loss of territory for Russia.
General Lavr Kornilov attempted a military coup d'état in September 1917 when his troops approached Petrograd while Premier Alexander Kerensky branded them counter-revolutionaries. His troops were arrested by the now armed Red Guard after the Soviet provided arms to the Bolsheviks.
Most government offices were occupied and controlled by Bolshevik soldiers on the 25th of October 1917. The last holdout, the Tsar's Winter Palace on the Neva River bank, was captured on the 26th of October 1917.