Step 0: Know your inspiration.
Step 1: Monitor what you are eating
You can’t jump into changing diet or lifestyle without an understanding of where you’re at now, and what you are doing. So without any regard to judging what you are doing, keep a daily log for a few days, of any and all handfuls of snacks, bags of chips or cookies, and of course meal items. Even if you don’t know exact calories, just write it down, all of it If your meal was a half pound sloppy burger with jumbo fires write that down. As you acclimate yourself, and particularly if your state publishes calorie counts for restaurant meals, you can over time get a handle on what all those calories add up to.
Once you have an idea of yoru daily intake, then you can use sites like About to add up calories.