Notebooks A5 2-Pack Player's Logbook
After all, they're first level, you're running a type you haven't run before, and your GM has been known to be a wee bit liberal with the wandering monsters.
So, rather than get 1 hard cover journal, and the commitment to that character's future that implies, get 2 soft cover Player's Logbooks. All the session tracking goodness of the hard cover Player's Journal, but a softer landing if things go badly south.
Both A5-sized booklets have over 70 pages of session notes and grids for making maps. They come in both red and black, and when you're done, and your character has surprised you (and maybe your GM), you'll have a story of adventure you can keep.
And if you're feeling more confident in their future, buy them a Player's Journal, and capture their full glory, at least until a wandering monster gets them."