There really is no shape of the universe. It is like air, it really has no shape. But maybe many, many light years away it reaches to the end of the universe and it has shape. But right now our technology cannot tell, or go that far.

Since all of the planets, and moons, and stars seem to have a spherical shape, it is possible that the universe may be a sphere.

No

The universe's shape is unknown, therefore we cannot tell where the earth is. but compared the the universe the earth is a tiny tiny speck

big bang explosion