If I were in this situation, and the goal is to draw an owl, and I can spend a year on it, then I'm going to spend an hour tonight looking at owls and maybe doodling a bit. I'm not going to worry about getting the owl perfect right away. Maybe next week I'll get super into owl feet, and the week after into learning good drawing posture. At some point I'll definitely be attending some meetup of nature-drawing enthusiasts.

I'm going to combine a general direction with a lot of time and horsepower and exploration and I will end up with a great owl drawing at the end. The odds are that I end up drawing the owl after only a few weeks because it's not as hard as I thought, but I discover some other really cool goals with a better payoff by then.

There's a lot of alpha in spending an unreasonable amount of time on interesting goals.

To answer your questions directly:

> How will an otherwise relative newcomer know what would be considered challenging

Just pick something that sounds challenging to you! You will learn a lot about what the scene considers challenging/interesting as you go. You can always update the goal.

> how to go about making it happening

Research. Start with stupid questions about the parts that are initially apparent. Keep a list of things that you don't know how to even begin to tackle, and over time, deep dive into items on the list. You will find that the resources/tricks/approaches you have grows as you go.

> and that they can make it happen?

You just have to really, really believe in yourself and in what you're trying to do. If you keep your health, that is all you really need.