Please I’m confuse when backing a baby which month is the appropriate month to remove the baby hand outside, and also for a baby boy to be sitting down?
Just make sure your baby is comfortable when backed, their is no rule on how to do that. Also note that carrying baby at the front (i.e FRONTING like the KANGAROOS) is more preferable so as to be able to monitor the baby for anything unusual.
Sitting milestone is achieved from 5 - 6 months.
Their is no significant difference between baby boys and girls when it comes to their acheivement of developmental milestones. Moreover, you don't have to teach them anything, they do it by themselves as part of their normal development.