Transitioning to crib?

We are cosleeping with our LO because we were dying of exhaustion but now we might be ready to transition him to his crib.

How have you ladies done this?

Does it help to put his crib in our room?

How long did it take for your LO to successfully go down in their own crib?

Is 12 weeks too early to transition? Should I wait until he’s 6 months old?