Gravity waves don't attract things, like all waves what they do is propagate. If you imagine an astronaut (or blob of water) orbiting the earth, the part closer to the earth feels a stronger effect than the part farther away, so the object is stretched out, to point towards the earth, if exaggerated it might look like an egg or if very exaggerated, it might look like spaghetti. That's what gravity does.
So a gravity wave is oscillatory, you can pick directions orthogonal to the way it is going and those directions are directions which alternatively be compressed or elongated (so spaghetti in one direction, then spaghetti in the other direction).
Just a electromagnetic waves can be polarized in different directions you can imagine x and + as two complementary kinds of polarizations, each long line takes its turn being the direction the spaghetti points.
And just like sound waves or electromagnetic waves can destructively interfere, so can gravity waves. In fact a perfectly spherical mass can expand radially in and out and no net gravitational waves are emitted because they destructively interfere. A non symmetric body that expands in and out emits gravitational radiation.
But even when you emit no gravitational waves you still interact gravitationally. Some effects of gravity can be stopped, and others cannot.
For instance if you have a hollow massive spherical shell, then the spacetime inside is flat, as if there is no gravity, and the spacetime outside the hollow spherical shell is curved, so there is detectable gravity on the outside.
However clocks inside the hollow spherical shell tick more slowly than clocks outside the shell that are very far from the shell. That effect can't be shielded.
And that might be a good way to think of gravity's primary effect, to affect the rate of clocks ticking.