I agree with the whole starting off slow thing. Diet is a big part of getting healthy. I'd say cut way back on the soda and try and get your eating habits under control first. No real surprises in the food dept, chicken, lean beef, fish, fruits, veggies etc. Most people know what’s good for them you just have to commit to eating the good stuff and not the fast food or vending machine carp.
For me simple is better; the easier it is to buy, make and eat the more likely I am to eat it. I’ll grill up a few chicken breasts Sunday night and freeze them then take em to work with me. Turkey sandwiches are good PB & J. What ever you like and can make simple for you the better off you’ll be. You can spend all sorts of money on “All natural foods” and special snack packs etc, but if it doesn’t work for you then it doesn’t work. Start simple, start small and you’ll have more success. You can get into the details of a more balanced diet later, but to start a turkey or chicken sandwhich for lunch is better then Chipotle.
With that in mind, wake up every morning or afternoon and do 3 sets of push up’s sit ups and leg lifts. As many as you can without killing yourself. All you’re trying to do at this point is build healthy habits again. Once you’re bustin’ out 60-80 of those a day, then look at a gym membership or pick a hobby that you enjoy doing that involves a work out, indoor soccer, hockey, running, boxing, whatever. If you enjoy it then you’ll be getting in shape without working. If you get a gym membership having a committed and good workout partner is a BIG help.
But above all start small. You’re not going to returns to your 17-18 year old self in a few weeks. If you want to get there again it’s goanna take time so give yourself a chance and don’t over do it.