I've interviewed a handful of people for junior positions, so take this with a grain of salt. I usually look for:

* Basic coding ability -- maybe a couple simple whiteboard questions, or walk through some code

* Able to learn things -- talking about past projects, interesting things they've learned, ask them to explain their past work to me (doesn't have to be tech)

* Able to ask decent questions -- Unfortunately I don't have a good standard for this, but generally I like candidates that can form a straightforward question about the role, the company, the tech stack, really anything.

Basically for a junior position, I am not looking for someone who will deliver a lot of value on day 1. Instead I am looking for someone who is curious, learns quickly, and can learn the necessary skills to deliver value later. A quick learner will be great in a year, a slow learner or someone who doesn't care to learn will not.

Good luck!