You have already started on the road by recognizing you are not where you want to be. Sounds like some philosophical bs, but it is true, you know you need to start, this is a great place.
Similiar to you, I was there about a year ago, out of shape and had been away from the gym. I was about 265 a year ago, I dropped down to about 235-240 and maintained that till this year, and then took another step to drop down more earlier this year. So, I have been there and then some.
So, what worked for me, may not for you, but I am sure with all the great advice and opinions, you will find what works for you. So, what I did is the following:
Exercise:
Started off with cardio about 3-4 times per week to get my systems jump started again. I tracked everything so I could make sure I was making progress, whether in speed or distance or whatever to get a base. This motivated me to do more. I added resistance training back in after about 3 weeks, starting off with just compound movements(Bench,pull downs, shrugs, presses,etc) and then added in more isolated movements. I also reduced the cardio after I started devoting more time to the weights. Lets face it, I can not spend 3 hours in the gym, I have too many other responsibilities that the younger crowd does not, about an hour to an hour and half is all that is needed. So, weights are 4-5 days per week, sometimes 6, cardio now for me is limited, but I will add more back in as we get into winter. Bottom line with exercise, do the exercises that you like to start with, take your time and keep in mind what your goal is, if you want more muscle, you need to train one way, just to be leaner, more cardio. But the more muscle you have, the more calories your body burns and more calories it requires.
Diet:
I did what everyone else is saying, drop the carbs. Again, i tracked everything to a "t", it worked for me to keep me on track. I even made a spread sheet up to make sure everything was totaled and accounted for. get away from the sugars and white carbs - white bread,white rice, etc. Increase the protien to help maintain the muscle and grow more, your body will steal from the muscle as well as from fat stores, so more protien will help, 1.5 g to 2.0g per lb of weight(thats goal weight). lean protiens goes w/o saying, add in protien drinks a couple per day is good. Reduce fat, 50g per day is a good goal, but you need some fat, omega 3 helps reduce fat around the mid section. track your calories and what you are consuming until you have a good idea of what items contain what for calories,carbs,fat and protien. Also, Eat more often, 5-6 times per day, just smaller quanities. I actually found that I was having a hard time getting enough food in at times once i started looking at the pattern and tracking everything. make sure you do not skip meals, and try to avoid eating too much late at night. Cottage Cheese is an excellent late night snack as the high protien will help and cottage cheese is higher in Casein which is a slow digesting protien which will help at night.
Supplements: a good quality Multi is critical, you will be depriving your body in some way or form of nutrients unless you can eat perfectly and again, reducing calories, exercising will all throw your body into stress, this will help. I would also get fish oil and Protien powder. thats a good start, if you need more info or further ideas on supps, send me a message and we can chat more specifically.
This is a general idea and good luck to you. intially the weight will come off faster as you drop water weight first, but if you are dropping 2lbs a week, that is a good place to be.