Hi pineapple, welcome to the online journals!
In regards your fitday/daily plate I can't really say : when I used fitday I entered almost everything as a custom food. When you enter something make sure that you double check the calories with those on the package (if the food has one) For things like fruit etc. there may be a discrepancy as perhaps fitday considers a 'medium' apple to be a different size to dailyplate.
Just choose one and stick with it. Keeping a food journal will help you see patterns in your food consumption and relate it to your
weight loss. So if you do not lose weight in say one month, your dailyplate says average of 1600 calories per day for the month, then you either drop your calories, manipulate the calorie distribution between macronutrients, or increase your exercise intensity.
I prefer the daily plate now mainly because it has a far larger food database. However fitday is somewhat more simplified and easier to view results. So it is up to you!
To me your calories look low, but if you currently do no exercise at all perhaps you don't need more. I suggest you get your butt to the gym immediately and start moving some iron around! Get thee to a treadmill!
In regards the weighing, as pierini says it depends. I think generally it is good to choose a day of the week and weigh that same day at the same time every week. First thing in the morning after you pee will give you the most accurate reading as there will be little fluctuation due to food or water in your system (weighing after you have eaten makes it difficult to compare results)
now some questions
How tall are you?
Do you have specific goals?
Do you always eat this number of calories?
When was the last time you had a fitness routine, and what was it?
good luck!