No conflicts in the advices. Many (most?) people live their life with default settings, simply going along with and never questioning expectations from the world around them (the life they were born to live). They're simply the instrument of a self-fulfilling prophecy. To be who you want to be, you need to be willing to change those default settings, even if that runs counter the predictions.

If you are happy being what you are, don't change, and just be yourself.

But sometimes whatever you are happens to be something like being overweight, or unmotivated etc. That's when 'being yourself' isn't very helpful.

The act of aspiration necessarily includes being willing to be a different person by the time you accomplish the goal you are aspiring to.

It depends on what your definition of "being yourself" is.