I would like to know whether an axial tilt on planets will affect their orbital angular momentum since I am creating a homework regarding angular momenta of planetary bodies in the Solar System.
Well according to this website:
There are two contributions to the Earth's angular momentum: the spin angular momentum of rotation about an axis through its center of mass, and its orbital angular momentum about the Sun or mass center of the solar system.
The axial tilt probably doesn't affect the angular momentum. Since the equation for specific relative angular momentum is:
Here's more information on Wikipedia.