In today's more balanced Livermore Tri-Valley market, expect roughly 30 days from acceptance to closing for a financed purchase, sometimes 21 days for a strong, well-underwritten buyer, or as little as 10–14 days for an all-cash deal. Your timeline will depend on your loan type, appraisal scheduling, and whether the seller needs a rent-back period after closing. Build in buffer time for inspections and loan contingency deadlines rather than racing to the shortest possible close.
You can put as little as 3.5% of the purchase price as a downpayment. However 20% or higher is more attractive particularly is there is a lot of competition for the property.