Do you mean as a school nurse? Depends on the state. Many states require school nurses to hold a minimum of a BSN/RN and a post bachelor's certification in school nursing.
The scope of practice varies by state, so while in rural TX an LVN may work in an acute care hospital or critical care unit, an LVN in CA or LPN in NJ would not be able to work in such a capacity. Many LPN's work in home care, sub acute care, nursing homes.
I'm in GA and school nurses are LPNs. I've only worked in offices because I want my evenings/weekends/holidays free to be with my kids, but most LPNs are in LTC/SNF facilities, offices, and urgent care.