I cannot second this enough. When I was just starting exercising I was overthinking things and it was a waste of time. The important thing at the beginning was just to start doing something.

Once I started hitting plateaus then I started reading again and tweaking my routine to help get past them, but that was after several months working hard to develop a solid base.

Now, after being in grad school for a couple of years while working full time and raising kids, I lost a lot and I need to start working on my baseline again, but that is another story.