Two things you need to know from the onset: 1) fast weight loss schemes lead to fast weight loss and even faster weight gain and 2) training programs that drive you into the ground day in and day out lead to injuries and burn out.
Now that we have that out of the way we can get to the important stuff.
I can appreciate someone who leaps in head-first into a new training program and brings their best to every workout, every day. But I can also appreciate someone who shows up three or four times a week, year after year, and gets the work done and goes home.
One person gets in "shape" fast but also gets nagging injuries and other issues that keeps them out of the gym after a while.
One person gets in "shape" slow but steady and avoids nagging injuries that would keep them out of the gym.
It's really up to you. If you want to burn the candle at both ends that is completely up to you. But, if you are interested in setting a foundation of strength, coordination, mobility and endurance and maintaining it for the next couple decades... well, I'm anxious to meet you in person!