When you use tell/told, the question is "told who?" and "told what?" So the pattern you use is "tell (someone) (something)." When you use say/said, the question is "said what?" If something is said to someone, then you always include "to" before the person.

Thanks so much Yasmeen Khan

'Tell' is transitive verb and requires a direct object while 'say' is intransitive and does not require direct object.