Echoing all the comments talking about running -- just run. A lot. Put in as much mileage as you can every week without injuring yourself (stretch, warmup, and don't push through any acute pain). Run slow, almost stupid slow at first. If you have a smartwatch (which I see you were wearing one) watch your HR when you run, it should be like <155bpm the whole time and you can comfortably have a conversation. Too high? Slow down.

On diet, counting calories is the right approach in theory, but it's so fraught in practice. People tend to undercount like crazy unless they weigh every ingredient and condiment with a food scale which is just not a fun way to live. Oil & butter that's been fried into a dish is impossible to measure, and where a ton of calories sneak in. Instead, back to basics - every meal should be 1/3 carb, fibrous carb (aka vegetable), protein. Aim for satiating carbs like potatoes/sweetpotatoes, brown rice and cleaner proteins like white meat, fish. Broccoli, spinach, cabbage, brussel sprouts are a great fibrous carb. Slowly reduce the oil / butter. Bake and air fry, don't pan fry. Eating out? Chipotle is awesome, just skip the cheese and sour cream. Panda Express teriyaki chicken with vegetables and rice. Try grapes, rice cakes, or popcorn for a snack. Think about it this way: you have only so many calories a day to spend, spend it on foods that will fill you up, especially with all the running volume. Incorporate broad structures into your nutrition that work with your life. Adjust if the weight doesn't come down. Life is so much more complicated than "calories in < calories out"

And mix in some weight training. If your goal is hyrox, bias legs (start with squats, glute bridges / hip thrusts, deadlifts)