How to get brighter teeth?

Okay so Im 14 years old and I brush my teeth twice a day ... But my teeth dont get brighter they're yellow so I was askin about like any natural stuff thatt can brighten it ... Like I just tried lemon juice + vineger + toothpaste (not such a big amount from each) and yeah they kinda got brighter ... So is using them dangerous for my teeth or what?? And how many times do I have to use them ,,, and some ppl say baking soda? So where do I get it from and what is it? And also how many times do I use it? And ... Yeah
thank you so much <3 :) and no I cant go to a dentist! :(

hey no I dont think vineger lemon juice or toothoaste would be harmful for you. maybe whitening strips I know your 14 but they cant cause any damage so maybe you could do that. I dont really know a lot about the subject though so im probably not a good person to ask.