But I don't know for which PIC this command is valid (because I imagine it varies depending on the PIC used?)
intcon is not a command, its a special function register
while the intcon reg is fairly similar in operation across the pic spectrum you need to always consult the data sheet for your chip
to ensure correct usage for the type/s of interrupt in question

the data sheet also has a section on interrupt types and how to configure them
the data sheet also will spell out how to save and restore mcu context to incorporate in your isr [interrupt service routine]code
the data sheet also has a section on ioc [int on change] for the gpio on that chip


What would then be the commands to activate the various interrupts on GP0,1,2,3,4 and5
there is no pbp command for that you need to set the appropriate registers yourself , properly of course

trisio,ioc, intcon