Do Botox or fillers really work?

Lately, whenever I look in the mirror, I notice my skin elasticity gradually decreasing,

I am incredibly stressed out because of the dark pigmentation and enlarged pores caused by acne I suffered from in the past.

Seeing people around me get Botox or fillers makes me hesitate too; as a complete beginner who knows nothing about it, I'm quite worried.

There were many kinds.

For skin like mine with large pores and acne scars

Do I need to get fillers?

Is it a Botox procedure?

Will I really see noticeable improvement with just one treatment?

I'm also really scared that my skin might become more sensitive due to side effects.

Could you recommend any effective treatments that are affordable even for skin like mine?

I would appreciate your good advice.