Welcome!
Calorie counting did the trick for me! I did get plenty of exercise, but nothing really strenuous until several months in. Taking walks with my kids, chasing them around the yard, etc. it all counts! Sometimes I would just put on some good tunes and dance with my little one. He weighs about thirty pounds, so I would lift and swing him.
I started with 1200 calories, but I had more to lose than you do. 1500 sounds perfect, and I'm glad you are aware that you might need to adjust up or down. Good luck!