I want to welcome you to the forum. I pretty much only do oil painting, but there are many excellent graphite artists here that will answer your question. I don't do charcoal or pastel -- well sometimes I use pastel to draw a picture on canvas to paint but that's about the extent of it.
I use Strathmore Bristol board for all my Graphite work.
I don't actually do charcoal or Pastel work, but if no one else has any ideas, I would try Strathmore.
They do paper, specifically, for Charcoal & Pastel.
They do different grades 300/400/500 series.
I used the Strathmore 500 series of charcoal paper for my hands picture I just finished. It was mostly charcoal I did use watercolor pencil too. I highly recommend it. I'm not going to use bristol with charcoal again. It falls off.
I, too, use the Strathmore 400 series.. but I also do watercolor.. and have found that the grain on Arches Watercolor Paper gives a really nice effect with charcoal.. You might buy a single sheet at your art store and try it out..