When starting on the path to become a healthier fitter human it is really important to decide how fit do you want to be? Do you simply want to be able to get up and down off the floor, walk up stairs without getting winded, and play with your kids for years to come, or do you want to look shredded and compete in athletic endeavors? The reason you need to know the answer to this questions is because each level of fitness comes with a lifestyle trade off.
On one end you can eat healthy 80% of the time, enjoy yourself 20% of the time, exercise three times a week, stay active the other days and maintain a level of health that will allow you to live a long happy life. On this plan might never see a "six pack", you won't be winning 5ks on the weekend, and you won't be competing on "America Ninja Warrior". For most of us this is perfectly fine and we will actually be happier than if we deprive ourselves of all the foods we enjoy and spend all of our free time training.
On the other end you can basically lock your diet down 100%, train religiously with specific athletic or aesthetic goals, and push yourself right up to your athletic potential. Doing this you might (and I mean might) be able to see a six pack or be competitive in any athletic endeavors. If this is what you seek keep in mind you will be trading off foods you love at social engagements, time for things like movies or tv viewing, and need to keep laser like focus on your final goal.
The truth is it doesn't matter where you fall as long as you pick the lifestyle that you can actually enjoy. Find your happy medium and stay there because that is sustainable for life. Do too little and you will find your health slipping. Do too much and you will drive yourself and your friends crazy and possible end in a binge or over training injury.
The most important thing in life is to be healthy and happy. Pick the plan that does both of these things for you and run with it!