Advice on workouts!

I am very motivated to start working out again. I have gained some weight and I would like to look stunning by next summer! Can any of y'all give me tips on meal preps and workouts that are efficient? Advice on not becoming lazy and keep going to the gym. My biggest problem is going for a month and then slowly stop going. Thank you so much. The first picture is me two years ago, second picture is my body now and the third is a girl that I have a girl crush on! She looks absolutely amazing and I would love for my stomach to look like that one day 😍😍❤️