Do I really need to use a hydrating ampoule during the change of seasons?

I'm debating whether or not to use a hydrating ampoule.
I've heard that you absolutely must use it during the change of seasons, and I'm curious if it actually makes a big difference to the skin.
I would like to know how many times a day it is appropriate to apply, and whether it can be used with other products.
I'm also wondering which one to choose between a light hydration ampoule and a rich hydration ampoule.
I am also wondering if the skin can become moisturized with just a hydrating ampoule.
Since it is my first time using this product, I am worried about an allergic reaction.
I want to see results quickly, so I would also like to know if layering hydrating ampoules is okay.
I'm wondering if using it consistently will help prevent skin problems.
I would also like to know if I need to adjust my moisture ampoule according to my skin condition, which changes with every change of season.
Ultimately, I want to find a moisturizing ampoule that suits me to keep my skin hydrated.