I'm quite new to programming and my projects getting big by my own standards. When I go to add a new feature im really struggling to evaluate the different options how/where to add it and im getting overwhelmed to the point of not progressing. I find myself wanting to seek some generic guidance from someone whos experienced but I dont know what the right question is to even ask. I want to ask things like "how should I structure a project" or "What kind of patterns can I use to keep my project manageable" "what do I put in code comments"

Practice and experience, but is there anything I can do to find the right direction to go to learn? I dont have the words to know what im even looking for at the moment I just have "pattern" like a design pattern and a notebook with a lot of boxes and arrows trying to plan out some kind of structure. I want to read something at least slightly relevant to game design and start trying to follow some tried and true guidance.

I made this post because I wanted to ask about when to expand a class vs. create a new one.

The example: I have a script (ResourceManager) that handles the resources on the game map it tracks loose items,items in storage, reserved items, delivery demand.

I want to add a crafting bills. These bills will want similar things(to reserve items, to making delivery requests, checking resource stockpile and once available the bill activates) and I can reuse a lot of the logic if I just put it in the same place. But its kind of different crafting and management of resources but them am I going to make a new script for every new thing at some point I just got to put similar things together right.

What kind of things should I be looking at when trying to evaluate these choices?