any pro athletes in training?

RidrxX122

I was wondering what types of workouts can build both strength and stamina while also staying lean. I have no idea where to start as far as a workout routine. I ride horses five days a week as well as being on my feet at the barn from 7a-4p and it wears me out. I have no idea what is too much in terms of exercise to improve fitness without over doing it. I am going to school for an associates in equine studies and exercise riding. I need to be able to gallop 10-12 horses /day and sadly right now in class we only ride 1 horse a day, and I still cannot consistantly hold the tough horses from day to day.
I am looking to lose around 10-15 more pounds with overall fitness being the goal, not necessarily a specified number, but for this job weight still matters.
I am 5'4 and currently weigh 137.

Also, as far as enough energy to do all of this while gaining muscle and losing fat, I'm not sure calorie-wise what I should be eating.

Hopefully this makes enough sense, haha. Any insight is appreciated!