I also try for the 40/30/30 rule but I agree with those who said don't bother if it seems too overwhelming right now.
It took me years to focus on the percentages and that was after I had lost most of my weight. I thought that it might help me lose the final few pounds and also just be healthier overall. Using a website to track calories (like Fitday or Daily Plate) helps a lot since it does the calculations for you.
I started losing weight only counting calories/WW points and it definitely worked but I started to worry about not getting all of the nutrients I needed with only a calorie total as my daily goal.
Short answer - do what you can when you can. If trying to do too much will put you off the whole thing, stick with calories for now!
Good luck!