It’s really important that you know how many calories are in the food that you are eating. Eating between 1500-2000 calories a day should see you lose weight but this does vary depending on your current stats.
1800 is a nice number to stick to particularly if you are also incorporating exercise into your day. You can throw in the occasional treat as long as you still track it as part of your daily “allowed” calories.
There are some apps that help you with this and a particularly good one is MyFitnessPal. Some other low calorie foods include eggs, fish and lean meat.