Regardless of what kind of PC you’re building ( home office or gaming), the components you need are going to be the same. It comes in handy to keep track of things. I also recommend keeping a list of what you want, what you have, and what your budget is. It even has a few example builds you can tweak to your liking. Not only does it have everything you need to buy, but it also lets you build your PC piece by piece right on the website and makes sure all of your hardware will play nicely together. To get a list of components together, no matter what your experience level is, you should use PCPartPicker. All of my most cost-effective PC builds have been slow-and-steady ones.
Grab components when they're cheap, hold on to ’em, and keep an eye out for a good price on what you need next. We've added buying advice to each category most affected by shortages to speak more specifically to each component's scarcity (or abundance now that prices are falling), but in general, just know that building a gaming PC, even as prices come down, might be a little more expensive than you expect. Please don't pay double or triple what any of these components are worth. In that case, my advice is to give yourself a hard budget. I’ve tried to stick to first-party sales, but sometimes components are just not available through anyone but a third party.