If you currently are in a stable condition with your diet, not losing or gaining weight and you don't have any other goals than being somewhat more active and to keep your weight, you shouldn't change much. Rope skipping and brisk walking aren't activities which increase your caloric needs by a big amount (depending on the amount of time you spend, of course).
For your goals there isn't any need for more control than just weighting yourself on a scale every week or so. If you lost some weight, eat more, if you gained too much, eat less. You could start counting calories, tracking everything you eat (and calculating the amount of calories in it), and calculate your caloric daily needs (eg with an online calculator or a simple formula). However, as I said above, I doubt that's appropriate for your goals.
As to protein, depending on your diet it is likely that you already consume enough protein, at least for your goal, which isn't to build a massive amount of muscle mass. The most common value is 0.8g of protein per kg of bodyweight per day. A standard western diet, or any similar diet that contains a lot of meat or other animal products (eggs, milk, cheese etc), contains more than enough protein, so you normally don't have to worry about it.
If you are unsure, you have to track everything you eat for some days and calculate the protein content it. That means, put everything you eat on s scale and check how much protein is in it. If there are no labels on packages, eg on fruit, you can search for the protein content online.
For your current goals this seems like an excessive amount of work, which it probably is. However calculating your calories and protein for some weeks, combined with controlling what you eat by checking labels and contents of your food, might have the positive effect of making you more aware about the stuff you eat.