What part is the most important part in building a project? All of them! Okay, bad joke. Selecting the right parts or components for a design is an area where both new hobbyist and veteran engineers struggle. The wide variety of devices make it almost impossible to know if you are selecting the right one.
Looking at a curated List, using component search engines and browsing DIY shops are how I tend to find parts for my projects.
You might want to bookmark these some of these sites so you can use them next time you’re stuck on how to find parts for your project.