So it’s fairly straightforward. You just need to find a website to help you work our your TDEE (total daily energy expenditure).
So for example - my TDEE is circa 1,700 if I do zero exercise and don’t move. I mean none. Not even breathing 
You need a daily calorie deficit of at least 500 from that to lose weight. Which would take me to only 1,200 cals a day.
However, I am very active and burn around 1,000 cals a day from running/walking/weight training. So to maintain my weight I’d eat 2,700 cals. I can still lose weight slowly on 2,200 cals (but I have a fair bit of muscle), but I eat 2,000 for weight loss.
Ideally you need to do 10k steps per day minimum to be able to eat a manageable amount and not starve. My steps are usually 20-25k a day but that’s not doable for most people.
At your height and weight I think your TDEE will be slightly higher than mine, so build your exercise around that. But check and see.
And fill up on protein, fruit, veg etc before reaching for crap!
Good luck