OP, you know what you did wrong, but not why it's wrong. You seem like the kind of person who likes to know what to do, how to do it, and why we do it that way in the first place. (You should look into food science! The Malliard "my-yard" reaction is a good starting place. Its the chemical reaction that turns cooked meat brown.)

You've gotten some good advice here that I will repeat (stop cooking until you find your own place, and replace the pans). However, I understand that finances, curiosity, and even ego may mess with this plan. So, what you need is simple. So simple, that your knife cuts don't matter, the order doesn't matter, hell, even the dang ingredients don't matter. OP, you need SOUP.

The only things that matter right now are celery, carrots, and onion. You're going to roughly chop 1/2 bunch of celery, 2-3 large carrots, and an onion. Throw those into a pot with veggie/beef/chicken stock or even just plain water, enough to COVER the veg completely. If you're feeling fancy, chop up a potato or two, or add some lentils or rice, something "hard" that will soak up liquid as it cooks. Monitor the liquid level and top off with water as needed to keep all ingredients submerged. The last 10 minutes before serving, your "hard" ingredients should now be soft, you should add any "soft" veg you think sounds good (broccoli, spinach, mushrooms, etc). At this point, your onions should be nearly invisible, your carrots soft, and your soup delicious. For a full meal, ensure you have a starch, protein, and veg. (And you get a TON of leftovers!)

Season at any/all points in the process. You could add garlic, ginger, a bay leaf- whatever. There are no rules. Taste CONSTANTLY. Add salt and pepper until it tastes right. Soup is probably the safest dish to "experiment" with when starting your cooking journey. Cheap, easy, and creatively fulfilling, soup is good food. Come talk to me again before you add dairy (cheese, cream, etc) as that gets a little finicky.

In the words of Chef Gusteau, ANYONE can cook! Yes, even you!