As a single dude, you want to cook in bulk and freeze and just heat up as needed. You will just waste food if you try buying ingredients and never freeze them. The only way that will work is if you're just buying a few bananas and sandwich ingredients, or flat out junk like cookies and chips.
Honestly, my eating habits are so sporadic and irregular that I can't even tell you what I eat since none of it is on a regular basis. I still have some stand-out advice though:
1. Eat a fairly large breakfast, ideally around 10-11AM I eat 1 large egg, 2 pieces of bacon, 1 biscuit, and 2 pieces of dark chocolate usually every morning, but not always. I sometimes skip breakfast in favor of intermittent fasting.
2. You won't be craving lunch but you might get hungry around 2-3PM in which case chips with pre-made dip/salsa, nuts, or fruit will tide you over until dinner.
3. For dinner, take something that you've made in bulk like burritos, casseroles, chili, shredded chicken, etc, and pop it in the microwave.
The best advice I can give learn how to control your portion sizes. When you begin to eat out less, you'll begin to notice this. Eat slowly and know that it takes on average 20 minutes after you're full for your brain to actually realize it. You will know exactly how much you need in the future and you'll wonder how the hell you ate so much in the past. Also, get in a routine. Eat the same stuff for a while just so you get used to thinking "oh, I need to cook" when you're hungry. I eat nearly the same stuff all the time through rotation and it really never gets old.
If you're going to actually make bulk-cooking and cooking your own meals work long term, you're going to need to have some room to cheat. I buy Trader Joe's Mandarin Orange Chicken and eat that with some freshly cooked rice (or you could have the rice already cooked and frozen to heat up) to eat about once or twice a week. There are obviously other options. Most frozen stuff flat out sucks, and none of it is going to be healthy (besides pure vegetables), but it keeps you from going out and keeps your mind focused on preparing your own meals.
It doesn't have to be complicated. Most meals are comprised of a meat/protein, a grain, vegetables, a sauce, some spices, and a cheese to make it fancy. With this approach, you can literally do anything you want. After cooking some basic meals for myself, I no longer desire to eat out. I am perfectly fine making "whatever" at home. It's not always as good, but it's good enough and it fills me up. And then again, some things are better than what I could get eating out - way better.
It's definitely hard to get started but it's very much worthwhile. You'll feel better about yourself, save money, and hopefully be healthier.
As far as how much you should be spending - that's debatable. I don't recommend trying to survive on pasta, beans, and rice. Vary your diet and eat plenty of fresh fruits and vegetables. It's not always going to be the cheapest but it's worth it in the long run for your health. I'd say eating under $7 a day is very doable for a highly varied and healthy "meal plan".