Hilton HHonors/Gold challenge question

I recently joined Hilton Hhonors and started the mvp gold challenge and had a few questions.

So far I have two stays. I am considering a longer trip next month with several stays. After I complete the challenge will I be able to get gold status for the very next night?

I also have utilized the double dip option and selected my united account. How long will it take before the miles earned by my hilton stay show in my united account? Is this the best option for utilizing the double dip?

Does anyone have advice on anything I should say or do when checking in during my stays (e.g., should I ever ask if there is an upgrade available, is there any other things I should do during the stay to maximize my rewards earning?). I have never participated in a hotel loyalty program, so any advice would be appreciated. Thanks!