use garlic and lime juice on pimple in my face which bring bad dark spot on my face

I wouldn't try any other natural remedies right before your show since it could make things worse.

Try using make up to cover up the dark spots.

In the future, try this proven acne regiment.

1. salicylic acid face wash in the morning
2. gentle face wash at night
3. benzoyl peroxide (2-2.5%) cream before bed

Good luck!