All this depends, if you are a person who wants to dedicate yourself to a specific sport, such as bodybuilding, powerlifting, weightlifting, or others, you may need a personal trainer to guide you correctly and supervise you, but if you are a normal person who just wants to train and improve your physique a little I do not think you need a personal trainer, since as you say, you can find almost all the information you need on the internet.