The answer your teacher wants to hear is that CH3F hybridization is sp3. CH3F (also known as methyl fluoride or fluoromethane) has a tetrahedral centre and bond angles of 109.5 degrees. The VSEPR notation for a molecule like this is AX4 or AX4E0. You might be more familiar with similarly-shaped molecules like methane and dichloromethane.
The carbon has sp3 hybridization, and the fluorine is sp3 hybridized as well. Hydrogen atoms do not hybridize, so that does not apply here.
The Lewis Structure is shown here. It has three hydrogen atoms single-bonded to carbon, and one fluorine atom single-bonded to the same carbon atom.
and you can watch it get drawn here, which emphasizes the tetrahederal shape and CH3F hybridization: