I think a big misconception in the field of health and fitness is that there must be one, singular correct way to do it. Everyone wants to fight over what is "right" and what is "wrong".
In reality, the process of training is one giant experiment you are doing on yourself!
The process you'll go through looks different for everyone. Of course there are scientific facts on why you definitely need to do certain things (like following a calorie deficit to lose weight). But at the end of the day, your success is going to come from having a very open mind and allowing yourself to adapt once you've learned new things about yourself or how your body behaves.
Trust the Process?
The "secret formula" will end up being consistency. There are thousands of workout programs, and a lot of them will get the job done provided you are consistent.
Take something new, say walking an extra 20 miles a week. If you did that for just a week you would probably observe very little changes in your body and likely feel like it was wasted effort. Keep up that mileage for a month and I guarantee you'll notice progress.
After you have seen a change, or potentially not seen a change, then you make an assessment and make changes accordingly. This is often explained by people saying "Trust the Process." This boils down to patience in most situations, but trusting the process doesn't mean blindly trusting. You have to keep an observant eye open on what your training is doing.
The "process" then becomes something more like the scientific method. Knowing that you are a person and not just another data point, use this method to optimize YOUR success.
"Rome wasn't built in a day, but they laid bricks daily" -John Heywood
Common Factors to Test
There are so many factors to health and fitness. So many that I can't possibly cover them all here. So let's use just a few examples, and hopefully one applies to you or can be applied in another way.
Recovery
A big way I see new athletes training is without a sense of their recovery abilities. It is one of the reasons you will have a hard time following any program blindly.
Athlete A is performing their favorite influencer's workout sessions. What they may not be aware of is that the influencer is performing those training sessions based on THEIR recoverability. Someone that has trained for years and years will have a much better understanding of their limits, and also will need much more stimulus to make progress than a new athlete will need.
It works the other way as well. Let's say Athlete B is unaware of what their body can handle to the point they don't train hard enough. They are doing fewer sets and reps than their body can handle, and therefore leaving gains on the floor. Athlete B may underestimate how much they can handle, and then wonder why they haven't made the progress they expected.
Both of these scenarios can be handled with the same method; observe and make changes as necessary. Neither athlete should just trudge along their respective programs hoping it will all work out. The ideal situation would be for Athlete A to dial it back after realizing they couldn't recover from the amount of work in the program, and for Athlete B to realize they can handle more and adjust the program to push themselves harder.
Nutrition
I preach the same formulas and standards that most good coaches do. Those formulas have limits though, and that limit is you.
The ways we calculate your target calories and how many calories you need to burn to lose or gain weight are all based off of data and fictional people. This means they are GREAT for guidelines and starting points, but will still require adjusting!
Take the calorie deficit for example. The typical recommended deficit for losing weight is 500 calories each day. This is a manageable and sustainable amount, but it is not a hard and fast rule. The best thing to do is use this as a starting point and be consistent with it for at least 4 weeks. If you don't notice changes then you'll need to adjust it.
Another thing that trips people up is following their same target calorie intake for years on end. The target calories you need to eat or need to burn are based off your current body weight. As you go through a program and lose or gain weight, your target calories will have to be adjusted! If you lost 40 lbs in a year and the following year you're using the same numbers, then an error has definitely taken place.
Timing
Trying to decide when is the best time to eat or when is the best time to train has a lot of focus on it as far as fad diets and exercise go.
Honestly, there is no best time. You will need to decide that for yourself. You can try working out at the crack of dawn for a couple of months and maybe you're making progress with it. Suppose though that getting up that early didn't allow you to have a lot of sleep or didn't allow you to eat a substantial breakfast to fuel your workout. Both of those factors will inhibit true hard work in the gym, and it might be worth switching you schedule around to see if you can lift heavier or harder with a new routine.
Conversely, maybe you are exercising after the business day and just cannot find the enthusiasm to lift truly hard. You're tired from working all day, you're unmotivated, and you want to go home and lay on the couch with some comfort TV. Changing your routine to a different lifting schedule may allow you the opportunity to make more gains.
There is no "right" way to time your days out. You have to experiment back and forth and see what works best for you.
What's the Bad News?
Okay there really isn't any "bad" news. But all of this experimenting comes with a cost a lot of people hate paying: time.
The fitness journey is ongoing. There is no set time limit. Observing all of these factors and truly understanding your body and the needs of your body will take time. Let it take time! It is one of the most rewarding journeys you can go on.
Keep an open mind, ask questions, make observations, and keep going!
Remember, "Rome wasn't built in a day, but they laid bricks daily" - John Heywood