Gates is from the Old English geat (gate, opening) — a surname for one who lived near a town's main gate. Henry Louis "Skip" Gates Jr.
Gates does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Gates reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.