Which teeth whitening method is the best?

I'm very interested in teeth whitening.

Maybe it's because I drink coffee frequently these days, but I think my teeth have become yellow.ㅠ

Will my skin become significantly lighter if I undergo whitening treatment?

How will it proceed?

I don't know what to do if I have to go to the dentist!

It seems that using whitening toothpaste doesn't have much effect, ㅠ

Please let me know if you have any good methods.