Not the worst way to do it.
As you're 14, I'd advise against weights for now, but I'd say stick with what you're doing, keep it on a normal, low level, steady state setting, then after about 6 weeks, when your body starts getting used to it, use an interval setting at low level and go from there. You may be able to increase the inteval intensity every 3-4 approximately.
You'll need more calories though. 1,800 is the average for adult sedentary females. In your case I'd look to go for around 1,600, as you're 14 and could go for that.
Depending on eating habits add some in to current meals and consider maybe adding another meal into the equation.
Your body will benefit better in the long term, from having more nutrition to build and grow with and the added calories to burn, to assist with fat loss

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Good luck yeah and
congrats on trying to look after yourself properly. You should be so proud of yourself for this and I hope you can stick to it. We'll be here for you every step of the way if you need us, okay

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You seem like a really warm, genuine and intelligent "young Lady" and I hope it works out for you

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