Bonsai from seed

Hello,
I have been trying to find information on when to repot, shape and / or prune for when you have a seedling, I made the jump into bonsai from a starter kit on Amazon that I got myself and brother as a Christmas stay in touch gift. However mine is growing very well, and I am struggling to find information regarding what the next steps from seed growth are. If anyone has articles they would like to share or if someone would be willing to simply help a beginner please feel free too. It would be greatly appreciated!