Doubt in Soul and sects

Metta, According to Buddhism, the soul is absent but karma is there. How it's possible without Soul, Karma would present. After the death, due to the karma of a person, he will rebirth. If the soul is absent how he will take rebirth. 2nd doubt, In Buddhism there are 2 Sects. In Hinayana - Acceptance the teaching of Buddhism. In Mahayana - Acceptance of Idol of Buddha. My question is Buddha is a God or Preacher. Eh Ma Ho, SURESH BABU