Just Starting Out

I've been a fan of FB for years doing workouts here and there. However, I want to get SERIOUS! I current weigh 269 and am turning 50 this month so its time to get in shape and keep that lifestyle forever! I just signed up for the 2-Week challenge and just completed Day 1. I'm looking for suggestions once this challenge is over, what to do next. Maybe the 4 week?

Any advice is much appreciated.