Learn what each tool and commands does.
Start simple. Create some fake projects and have fun using the tools. If you want to start from the beginning then don't waste your time yet with the "how to make a glass effect on the letters".
Start with things like "how to create a business card", "how to resize an image", "how to create a layer mask", "how to make a clipping path", etc. All the very basic stuff.
Photoshop is like that art box every kid (well, at least me) ever dream of. It has pretty much everything you need to create almost any kind of art. You won't find any perfect guide to learn, you'll learn as you'll need to achieve some effect and then you'll learn as you'll find a way to create it. There's many ways to get to one result too. Have fun with Photoshop!
You need to know your tools before you can use them intuitively. You'll have your favorite ones. You'll try different techniques and also have some you prefer to use for whatever reason. Every designer started with the basic tools and increased their skills and knowledge of more tools by using them.
Using Photoshop as an expert is to become a master at it. You have no other choice than to get started and practice if you want to get there! There's also different kind of Photoshop experts... some are better at digital manipulation, others at using it for printing or color management, or drawing, or picture retouching, coloring, texture, etc. As @Vincent mentioned, you need to know what you want to do, that's already a good start.
Plus frankly, not to discourage you... after Photoshop you should learn a few more software like Illustrator and InDesign!
And if it can reassure you, some tutorials have a step missing but that can be a good way to learn to try to reproduce some effects on your own or find what's missing. The graphic design stack exchange has a lot of valuable advice and tricks too; I think I can safely say there's better tricks here than a lot of tutorials in term of quality of the final result. It's worth exploring the "photoshop tag."