SfBay/Manhattan: How did you save up that cash for down of your first home?

Hi Folks, I am 29 Year old SRE working in bay area planning to buy my first home in the near future. Have a couple of questions and would love to hear your stories.

How old were you when you bought your first home? How much % downpayment did you do? What advice can you give to someone like me (single) and making an average bay area salary of 130k to save up for that hefty downpayment? I don't have any savings in my bank account, its time to start. Don't know how many years its gonna take and the rent is taking almost half my paycheck.