I'm thinking of getting Botox for the first time. Is it okay?

Lately, I feel like my face looks big because of my jaw muscles, so I'm considering getting Botox.
They say Botox is a relatively simple procedure, but since it's my first time, I'm worried for no reason.
I heard that getting Botox makes your face naturally slimmer, so I'm curious about the extent of the effect.
I also want to know if there is any unnatural or uncomfortable feeling after getting Botox.
I would appreciate it if those of you who have received Botox for the first time could share your reviews or any precautions.