On or before July 1, 2024, the Department shall develop and design a new system of professional development that is tied to the career ladder. The new system of professional development shall include: Training on how to lead and mentor teams of professionals to promote professional learning among colleagues; Training on how to collaborate with colleagues to improve student performance; Training on how to design and support collaborative professional learning for teachers pursuing an NBC; A train–the–trainer model; and Advanced training on the science of learning specific to individual disciplines. On or before June 30, 2026, each county board shall provide the system of professional development designed by the Department under subsection (a) of this section to each teacher who teaches in the county. Beginning on July 1, 2026, each county board shall provide the system of professional development designed by the Department under subsection (a) of this section to each teacher teaching in the county no later than 1 year after the teacher begins teaching in the State.