I realize you take RER 8 to get downtown Paris it is about 8.50 E.
However I need to get off at Gare Nord and then take the Metro to My Hostel area 19.
Does this RER 8 go near where I want to go?
Can I buy metro tickets at the same place I buy my RER ticket?
Can I get all my prebooked train tickets there as well?
Thanks