YA Fantasy (?) about a guy who discovers he was born in a magical realm and has been hidden in our world by his mother

[A]

I read this book (series?) sometime in the 90s or 2000s.

If this book exists, I recall a number of specific details from it, so here goes:
the main guy is in his teens, I think?
he finds out about the magical realm when he's attacked in the real world (in his home?)
turns out his parents are both from the magical realm
he lives with his mom bc his father was killed (assassinated?) in the other realm
so now they are in hiding on normal earth
the guy has to go back to the other realm, alone (for reasons?)
the place is enchanted, iirc, but he doesn't know anything about how it works
he ends up in a boat (canoe?) going down a river through a forest
I think there are creatures and other dangers in the river?
at some point he spots a cabin on the banks and pulls over (idk boat terms) to stay there for the night
he meets a thief dude (?) and somehow they end up questing together
at some point there is also some kind of magical initiation test that was as simple as walking down a hallway or something
but the hallway or corridor was imbued with magic that tempted and distracted and tried to demoralize you

Okay, I will stop there. This is either a book I read and liked or the idea for the novel I'm destined to write. Thank you for your kind consideration, and I desperately hope one of you remembers this book too so that I can immediately buy it and read it again.

[Capn]

Some similarities to The Grey King, but in that instance, it is more of an explainer than an actual plot you follow... although, having said that, if you include the final book, Silver on the Tree, it could be a garbled version of the same?

[A]

Those sound interesting but are not the thing Thank you, though!

[Sarah]

Bit of a stretch, but maybe The War of the Flowers by Tad Williams?

[SamSpayedPI]

Some similarities to The Talisman by Stephen King and Peter Straub, with the mother hiding the kid in our world after the father is killed in the other.

I don't remember a boat, though, and the companion he meets is not a thief.

[Sue]

Pawns Dream by Eric S. Nylund? https://www.fantasticfiction.com/n/er...

[David]

Pawn's Dream by Eric S. Nylund for the GR link.

[Joshua]

Could this have been a book named Willow? Willow kinda traces Moses origin. Maybe it's the Legend of Willow. A baby is placed in a basket and picked up by a poor women who raises the infant as her own, until the time that the young man must brave his true identity.

[SamSpayedPI]

I'm not sure if this is the book Joshua is talking about or not: Willow. It's a novelization of the movie; the MC dwarf finds a baby human girl floating on a raft in a river, and tries to return her to a human family; the first human they happen upon is a thief.

There is a continuation series that takes place about ten years later, beginning with Shadow Moon

[Juels]

The Replacement by Brenna Yovanoff?