sounds like you are aiming rather for a generalist position or even possibly going freelance?
only you can tell if there's an area in 3D you wanna focus on, if you have no idea then that's probably your heart telling you it wants to go generalist... or make up artist, or zoo keeper ;)
while watching tutorials is good and essential it's not enough to memorize all the stuff. solving problems on your own is a much more effective way to learn. set yourself small goals, little fun projects you can complete within a week or two. doesn't matter if you have no idea how to do it, figuring it out is the fun part anyways. once you completed it, take a deep breath and move on to the next. prepare for not doing much else the next couple of years, and don't forget to always tip your pizza delivery guy.
as for your question about client work: it would be utterly boring if i always knew exactly how to do every task involved in a project. unfortunately this situation happens more often the better you get. so enjoy your lack of knowledge while you can and dive into it. btw, there's nothing "fake" about it, in CG even the people at big studios solve problems while working at a project. no one knows exactly how to solve any task thrown at him right away.
and of course, a demo reel can get you jobs. as long as it's good it's actually the very best way to get you jobs.
i hope that helps.