Strong soreness the first few days after changing your routine is pretty normal, especially if you've been without training for a while or you threw in exercises your body doesn't know 💪 The muscle gets a little inflamed as a response to the new effort, and that creates that pain you feel more on the second or third day (it's rare for it to be intense the same day). The thing is, if *everything* hurts every single day in a row, you're probably ramping up the intensity too fast or training every day without giving yourself rest.
Your body adapts pretty quickly - let's say in a week or two the discomfort is going to drop noticeably if you respect your recovery time. Some people say 3-4 weeks for everything to fully normalize, but people usually notice improvement way sooner. The key is not going all out with maximum effort from day one; it's better to increase gradually. Rest between workouts, light stretching, and staying hydrated helps.
What a lot of people don't mention is that if you try to "push through" the pain by training harder on those days, you just make it worse and your body takes twice as long to recover 😅 Take it easy with the intensity, give yourself rest days even if they're partial, and you'll see that pretty soon your body gets used to it and that soreness won't be so brutal.