I was pretty much in your physical state once... what I did was for the first two month was build stamina via Cardio training and mix workout(working out all the body parts) consider this as step one to muscle gaining.
You could control your diet but cutting down on oily and fatty foods and start watching what you eat(switch to boiled,grilled meat and fresh/boiled veggies - fruits as a treat).
1hour Cardio - You could interval train on the treadmill - Eg. run for 2 mins and walk for 1 min...continue it for 40mins and cycle for other 20mins.
30mins-Then the mix workout where you'd flex your back,chest,arms,should and leg(3 abs sets every second day)key- do more reps try to lift heavy by yourself...don't pick up weight where you'd require a spot....dont worry you'll get there later, in a month or so. Carry on with this for 7-9 weeks religiously.
this would help you,
1- Burn fat ( via cardio and food watch)
2- Help you get used to weights and gym equipments
3- You are preparing yourself to trim first and then bulk
4- If you follow this without missing out on workouts and hopefully a trainer can help you chose the 1-2sets for each body part (mix workout regime) you'll learn how to balance your weight lifting for the time being
5- you should have lost around 20-40lbs or more by the end of the 9th week(depends how hard you train)
6- Should get you started to your muscle gaining regime
7- you should've by the end of the 5th week started to feel physically and mentally fit!
Step 2 - Level 2 is only if you have lost weight and you are hooked onto your new routine .... I'd say knowing how much you have progressed ask a good trainer to guide you with a diet & workout plan.