How to treat yellowish stains on the teeth?

Hello doctor,

I have not been to the dentist in a while to check my overall oral health. I brush my teeth and use mouthwash but do not floss. I am using sensitivity toothpaste and black charcoal-activated toothpaste also. I recently bought the Hismile pack to help with stain removal and this also comes with a purple serum to help activate white teeth and get rid of stains. I have noticed the bottom half of my teeth are more yellow than the upper half of my teeth. I have some discoloration on my back teeth on the top of my teeth and the bottom teeth are yellow at the roots also. I have not received any fillings or root canals, etc I may have a tooth at the back that has come through only slightly but causes no pain. I receive universal credit also but I am anxious to use the dentist. I always suffered with this as a child also but did attend appointments. What should I use next as a service option? I was hoping to do a video consultation.