If the Earth were twice as big, there would be consequences especially regarding the force of gravity!
In fact, if the Earth had double its current radius, this would mean 8 times the volume and mass, but it would also mean double the gravitational force.
We would then be twice as heavy, because the gravitational force increases as the density and radius of the planet increase.
The mountains would be lower and flatter, and if you fell into the void, you would accelerate faster and hit the ground harder!
There would be more "stocky" life forms, with thicker bones, to be able to survive with this greater gravitational force.
The atmospheric pressure would increase.
And sending probes, rockets and satellites into space would be prohibitively expensive!
Air travel would probably also be significantly more difficult and more expensive!
The oceans would be even deeper and the moon would be closer, causing enormous ocean tides.
The core and liquid mantle would also be much larger, causing increased pressure and heat beneath the Earth's surface.