First order circuit with t=0+ , t=0-?
Understand the behavior of Capacitor. see this


In your circuit, Initially Switch was closed for the long time, nothing but capacitor will act as open circuit. Now reduce the circuit using series and parallel combination concept. You can easily find the Voltage across the circuit. This will give you Vc(0-).
Since Capacitor will not allow sudden changes in voltage. So Vc(0−)=Vc(0+).
Not sure about remaining questions but Generally you have to find the Time constant(RC) to find the voltage across the capacitor and substitute in this formula,

\$V(t)=V(1-e^{(-t/RC)})\$
Change the values of 't' according to your requirement.