Short answers, pulled from the story.
A clay tablet from Knossos bears the inscription A-pa-i-ti-jo which dates to the Mycenaean period. This Linear B script offers the earliest written evidence of a deity named Hāp'haistios and confirms worship existed long before Homer wrote his epics.
Hera cast Hephaestus from Mount Olympus because he was lame from birth. Another account claims Zeus threw him down after Hephaestus tried to save Hera from Zeus's advances but this version attributes the fall as the cause of lameness rather than its original state.
He landed on Lemnos and learned craftsmanship from the Sintians an ancient tribe native to that island. The island of Lemnos remained sacred to Hephaestus throughout antiquity and priests knew how to cure wounds inflicted by snakes using Lemnian earth believed to have fallen where Hephaestus landed.
Twenty bellows worked automatically inside Hephaestus palace on Olympus and they responded to his bidding to forge weapons for the gods. He also crafted golden tripods with wheels that moved themselves across the assembly hall of the celestials.
Some scholars suggest his lameness represents peripheral neuropathy caused by arsenic exposure. Bronze Age smiths added arsenic to copper to produce harder alloys during periods of tin scarcity and chronic poisoning would explain the disability common among ancient metalworkers.