you need to read more on growing before you start. just a heads up people don't like laziness if you cant help yourself by looking into things a lot of people wont even bother. some questions are definitely ok but this is a basic question that google or looking on this forum can help you with.
Do you mean light spectrum? 2700k for flowering 6500k for veg, or HPS for flowering and MH for veg. Depends what light system you got. 12/12 means 12 hours of light on 12 hours of light off per day (24 hours). 12/12 needs to happen for flowering to occur (buds) the 12 hours light off, the plant needs to be in complete darkness. Sure you can grow in 1 space and switch lights...