We follow the biblical commands and patterns. We pray [i]TO[/i] the Father in the name of Jesus (Jesus is the mediator and intercessor). We are never commanded (or shown a pattern or example) to pray to Jesus or to the Holy Spirit.

You say "it doesn't make sense," but I don't know why it doesn't make sense to you. The Father hears the prayers and is the One who answers them. We pray in Jesus's name, and He is the mediator and intercessor for us. The Holy Spirit prays with us as a Paraclete, or "one who is alongside." What doesn't make sense about it?

Why did human pray to father but not to jesus as human Form?

It doesnt make sense that christians prayed to god but not to jesus, because jesus is the son from god so they should pray to him!