Applying 5e PHB to existing character

I'm trying to make an Arcane trickster in an existing game, and have just found out I will need the PHB from the market place in order to do so. I would just like a little more information I can't seem to find before making any purchases. Could I get a hand with a couple of questions, or any information on the subject here that someone may be able to provide? Upon buying, does this automatically expand my compendium and allow the charactermancer to choose the PHB archetypes? I am not the DM, am I allowed to share the PHB with other players/the DM if I am the only one who has the PHB? And not being the DM will it even allow me to use PHB archetypes if the DM doesn't have the addon? Any help would be greatly appreciated.

Upon buying, does this automatically expand my compendium and allow the charactermancer to choose the PHB archetypes? Yes, this a core feature of owning the PHB or any supplement book. I am not the DM, am I allowed to share the PHB with other players/the DM if I am the only one who has the PHB? You can share it with others players in a game you've created, if you have turned on compendium sharing. And not being the DM will it even allow me to use PHB archetypes if the DM doesn't have the addon? You can use it even if the DM doesn't have it, unless they have disabled uses of extra compendiums. Check the Help Center for more info on how compendiums work.

Thank you! Andreas J. said: Upon buying, does this automatically expand my compendium and allow the charactermancer to choose the PHB archetypes? Yes, this a core feature of owning the PHB or any supplement book. I am not the DM, am I allowed to share the PHB with other players/the DM if I am the only one who has the PHB? You can share it with others players in a game you've created, if you have turned on compendium sharing. And not being the DM will it even allow me to use PHB archetypes if the DM doesn't have the addon? You can use it even if the DM doesn't have it, unless they have disabled uses of extra compendiums. Check the Help Center for more info on how compendiums work.