How should I prepare before visiting my future spouse's family home for the first time?

Come with the intention of honouring them and building a relationship, not just passing a test. Dress modestly, give salam, and show good manners to the elders; small things like these leave a lasting impression. Listen more than you speak, and ask about them sincerely. Avoid topics that could cause disagreement at a first meeting, such as politics or money. If you are nervous, that is normal; bring an honest and humble heart. Talk to your future spouse beforehand about the family's background and sensitivities. A good meeting builds a foundation of trust between two families. See khitbah (proposal).