Fantasy novel involving a contest with mounts and targets, and eventually a confrontation in the dream world

I believe that I either read this, or listened to it as an audiobook, somewhere in the last three years (2017-2020) due to me associating it with a particular commute on the Pittsburgh public transit. It was a book that I either read as an ebook, or listened to via an electronic copy. The protagonist (not sure if they were male or female) was younger than an adult, and had some sort of magical gift that led to them competing with other people with such a gift. There were several trials. One involved traveling through town and hitting certain targets. I believe that, for this trial, they were free to pick a mount to ride. I want to say that, at the outset, some characters were disqualified for them picking mounts that were not valid under the rules. The protagonist misses most of the targets, but scores some rare and high-scoring target in the town. I want to say that it had something to do with a fountain. Some time later, they’re in a different trial in a dream world. I have this vague memory of one of the characters being up in a lamppost or a tree, basically staying away from the danger, and the protagonist convincing them to jump into a lake, which turns out to be something which brings them to a later step in the contest, with some commentary about how these competitions are usually more competitive than cooperative.

I have a few other vague memories. The protagonist was in a house that was largely vacated. At some point, they messed with a part of the house that they were not meant to be in, and there was some sort of drama involving shadow puppets that turned into real things (I think they may have stolen a key that led to a forbidden wing of the house?. And I think the protagonist was sponsored by a renowned mage who had a son who lacked that sort of power, which might have led to some ill will toward the protagonist being a better heir. And I think she was maybe considered cursed at the outset, something where she was close to being lynched at the outset until she was sponsored by that mage.