In general the puzzles involve basic operations that any language would have. Functions, data structures, recursion, some amount of back-and-forth between strings and numbers and records. There isn't any reliance on library-like things like making HTTP requests or parsing complex file formats. I think they would be fine for someone starting out at coding.
Every day's puzzle has two parts. The first part is usually easy. The second part is then a twist that requires a change to the solution of the first part.
Apart from that, you can always skip a day if you just can't solve it. The exception is that sometimes a puzzle can reference the solution of an older day, so if you'd solved the older day you would already have an understanding of how to proceed, and might be able to reuse some code.
> I think they would be fine for someone starting out at coding.
The earlier ones, perhaps, but professional programmers struggle with the later ones. I’d never suggest that some one new to programming tries to do all of AoC.
It really helps to (1) have taken an algorithms class and (2) be aware of Python libraries that implement common graph algorithms if you're going for time. At least, that was my impression 2016-2017. The later puzzles are impossible if you don't know a good enough algorithm (they're more or less designed to take impossible amounts of time to completely brute force).
I'd suggest new programmers do any they can reasonably understand and just skip ones that seem like they'll be frustrating or require a "fast" algorithm they don't know. (OTOH, many days' first star can be gotten with a brute force algorithm. It's usually the 2nd star that takes something more clever.)
Every day's puzzle has two parts. The first part is usually easy. The second part is then a twist that requires a change to the solution of the first part.
Apart from that, you can always skip a day if you just can't solve it. The exception is that sometimes a puzzle can reference the solution of an older day, so if you'd solved the older day you would already have an understanding of how to proceed, and might be able to reuse some code.