If you have nothing to compare yourself with then there is no speed.
Speed is like marriage - you can't be "married" if you're alone. To define speed, you need an external reference. Then you say "my speed is XYZ km/s relative to object ABC".
This is what most people get wrong about speed. They think it's something you have in yourself, like the number of atoms, or the net electric charge. That is not true. Speed is always relative - you always, ALWAYS, measure your speed relative to an external object.
In a completely empty universe, where only you would exist, speed would be meaningless. You could not define your speed in any way, because how would you measure it? You need an external reference, always.
And to prevent another question that people usually ask: you cannot measure your speed relative to "space". Speed can only be measured relative to other things, and space is not a thing. Space is just the background where the relationship called "distance" takes place. You cannot grab the blue marker pen and put a big X on "space". But you can grab the blue marker pen and put a big blue X on an asteroid, and then say "measure speed relative to this".
So, if you move at 0.999c relative to object A, then space contraction and time dilation apply to you (and to A), as calculated from relativity. But if at the very same time your speed is only 0.5c relative to object B, then space contraction / time dilation are different as seen by B (or seen by you with regards to B), again as calculated from relativity. Object A will see a certain amount of space contraction being applied to you; object B will see a different amount of space contraction applied to you. Both are right.
This is why it's called "relativity" - because nothing is absolute, everything is relative, and it all depends on the relative speeds between objects.
You don't "contract" in an absolute way when you move - because motion (speed) is always relative. The contraction is just something that happens between you and the external object you use to measure your speed. Again, see the comparison with marriage - it's something between you and the other person, and applies only to the two of you.
By the way, that doesn't mean that space contraction is an "illusion". It is very much real. If you move at 0.999c relative to object A, you're shrinking length-wise from the p.o.v. of object A. But if at the very same time you're not moving at all relative to object B, then B will say your length remains the same. Both are right. Both are for real.
We grow up learning that length and duration are absolute and fixed, but that's just an illusion - that, actually, is the illusion. They're not fixed, they're not absolute. They're just relative attributes, that depend on your motion relative to other things. Relativity gives you the exact math to calculate the amount of length/time change, depending on relative speed (well, "relative speed" is like saying "wet water" - speed is always relative, by definition).
The only thing absolute in this universe is the speed of light - it's always c in your local frame of reference, no matter what. Everything else sort of shifts around and gets adjusted as needed.