Figure out how many calories you need to maintain your weight and eat less then that.
A calorie calculator can estimate how many calories you burn a day and can estimate plans based on how much weight you want to lose per week.
Exercise so that you don't lose muscle mass and your body burns the stored calories.
And finally, test things and find what works for you. Staying consistent is key.
For myself, I like a Zig Zag plan for losing weight cause I can still enjoy some junk food on the weekend. I track my calories using MyNetDiary because it syncs with other apps I use.
I've lost 15lbs in 4 weeks but I know it's going to take about 5 more months to meet my goal weight.
Good luck on your journey!