However, if you ask me to pick one specific project, I get overwhelmed because I don’t know what’s reasonable.

I don’t know enough to know if my ideas are achievable, or if I’d just be bashing my head against the wall. I don’t know if they’re laughably simple tasks, multimillion-dollar propositions, or Goldilocks ideas that would be perfect to learn a coding language.

List out some ideas you're thinking of. While it may not be obvious to you, someone who is seasoned (me or someone else) might notice at least a general theme or idea to point you in the right direction for where you should go and what you should learn, regardless of if the projects are reasonable.

Note - Most projects take teams to realize, so if your ideas are too large, they might not generally be feasible alone.

Feel free to comment some ideas

I don’t know enough to know if my ideas are achievable, or if I’d just be bashing my head against the wall.

Achievable is subjective, and even if you progress a ways and learn something that makes you realize that that particular project can't be achieved how you envisioned it, you still have the knowledge to either a) figure out new ways to achieve the same effect, or b) take to a new project.

Knowledge builds on knowledge builds on knowledge. If factor in not starting a project is not knowing enough to know if it's achievable or not, you'll never actually get the necessary knowledge to figure that out. You can't know how to do something until you try to do it...fundamentally.