1. The calorie deficit should be your number one priority
The undeniable truth is that energy balance dictates whether or not you will lose weight or not. If you are not in-taking less calories than what you burn, you will not lose weight. There are literally no outliers. Before you say it, yes it is harder for some people, yes people with thyroid issues or P.C.O.S find it more difficult but the energy balance equation remains the most important thing to conquer.
Basically, you must ingest fewer calories than the amount you expend for weight loss.