What is the covalent bond formation of methane?

Methane: CH4

Carbon has 4 . To achieve stability, it should follow the i.e. it should have 8 electrons in its valence shell.

Hydrogen has 1 electron in its valence shell and should have 2 electrons in its valence shell to achieve stability.

Thus, C shares each of its electrons with one hydrogen covalently to form CH4 and achieve a stable form.