Creatine will give you energy and help you gain weight as long as you eat right and drink plenty of water. However, expect to lose some of the weight and muscle once you stop taking it. I took protein and creatine when I first began to lift and it helped me put on weight more quickly. Now that I no longer take it, I lost a little weight at first, but slowly I'm getting back to where I was without the help of suppliments.
If you're looking forward to gaining weight and muscle, EAT!!! You can lift every single day, but if you don't eat 3500-4000 calories of food daily depending on your body weight, you won't see the results that you want. Don't just eat junkfood either, get down on some real shit. Turkey breast sandwiches, borritos, chicken breast, bannanas, nutri grain bars, etc. Take vitamins too.