
There are two things you can change about your body, how much muscle you have and how much body fat you have. A "Pilates body" has low body fat and maybe a little bit of muscle. You build muscle by doing any sort of resistance training for whatever muscle groups you want. You lose fat by eating less calories than you burn on average
There’s lots of Pilates workouts you can follow online, see what makes the most sense for you based on what equipment you have available. Also consider weight training ~3x a week, a lower body day, upper, and either full body or abs/core day. A lot of what you’ll want to obtain will be achieved through caloric deficit & cardio too so 14k steps (or max achievable) plus walking, spin, or running.