Hi -
There is no one web site or one YouTube video where you can learn Photoshop.
What I do recommend is you start with Aaron Nace and PHlearn:
phlearn.com
These are excellent basic tutorials of PS tools and capabilities that also includes practice files so you can work alongside.
From there it's a matter of finding some images to work on, pick an issue you want to solve, and then you can search YouTube for videos that address those issues.
The instructors that I found most helpful:
Aaron Nace - PHLearn
Unmesh Dinda - PixImperfect
Jesus Rodriguez - Photoshop Cafe
Marty Geller - Blue Lightning TV
They each have their strong points - my main complaint is they sometimes move too fast. But you can adjust the speed of the video by going to settings.
PS has a fairly steep learning curve but you can learn the basics in a brief enough time that you don't get frustrated. Just don't overreach too quickly or too aggressively. Yet never be afraid to try something new. Nothing is learned without risk.
Of course, hang out here and see what's being done. You can try the edits yourself but don't feel obligated to post. If you do, there are some great mentors here both artistically and technically.
Good luck with your adventure - be warned though, it can become an addiction!
- Jeff