If motion is relative, how do we have any real sense of direction

The earth moves relative to the planets and the sun.
We can compute the distances and angles and see how they vary with time

The sun moves relative to nearby stars.
We can detect the movement in some cases by the proper motion of stars.
In more distant stars it is calculated by using red shift.

The Sun appears to be moving toward the star Vega in the constellation of Lyra at an angle of roughly 60 sky degrees to the direction of the Galactic Center.

>> Direction is a meaningless concept ...
So how do you keep from getting lost all the time?

Astronomers keep from getting lost by using certain quasars. They have a standard list of 3414 "compact radio astronomical sources." These provide a pretty good concept of direction, without any need to worry about motion or lack of it.

You are correct in that any frame of reference is as valid as other.

However, all humans on Earth have some in common such as "down" being toward the gravitational pull against which one is being held. But in free fall, even that goes away.
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We only have a 'sense of direction' relative to some other object.
The good news is that we get to pick the object.
That's why we feel we are 'standing still' when not being accelerated.

Your questions are tiresome.

In your everyday life, have you <> had to worry about space-time and relativity in order to go about you business?

Our perception of movement and direction is relative to the Earth.