If you don't make it a habit, a lifestyle, you'll never get past getting started. Personally I think your goal shouldn't be to lose fat and put on muscle. If you 'really' need to lose some pounds then get some cardio going, hit the weights but not to hard. Once you have your heart in shape and see changes in your health and appearance, then worry about the beach muscle.
I'm not saying you can't do both, of course you can. What I'm saying is I see so many people who wanna lose fat, gain muscle, run a marathon etc.. all at the same time. Lofy goals just make it harder to succeed and easier to view yourself as failing.
Damn I'm ranting.
Diet really comes down to ensuring you get the protein, fats, carbs and cals you need to fuel the body while shedding some fat. Don't do some crazy low carb, low cal diet that leaves you feeling beatup all the time.
Workouts shouldn't be some olympian effort. Just get in there and sweat. Set some goals you can accomplish. Don't expect miracles and remember you are learning and set backs are common place.
Rant over have a good time here and in the gym.