Birth control, a few questions about it?

I started taking birth control pills Monday (June 27th). I'm taking Loestrin 24, my doctor said it would take 2 weeks to work, meanwhile I believe the information sheet said it'd take only a week. How long does it take to work? Also, I was reading some things that can weaken the effects of the pill and a couple things such as vitamin C and herbal remedies were mentioned (along with Tylenol and other medications). Would that mean I couldn't have things such as orange juice? And would herbal remedies include tea? Also, is there any sort of pain killer that wouldn't weaken the pill? I'm going to be using condoms even when the pill works, but I still want the pill to be as effective as it can so my partner and I can be as safe as possible.