Example of the use of ´´Já´´ used as already and Now:
.I have already gone to the market this morning-Eu já fui ao mercado de manhã.
.Go to the market right now-Vá ao mecado já.
PS:note that in the first sentence já means something that has already been done,while in the second sentence it means the order of doing something imeddiately.
Hope I have helped!