You can read an SDF file using the SDMolSupplier() function of the rdkit.Chem module to get the list of molecules.
Here is an example:
from rdkit import Chem
supplier = Chem.SDMolSupplier('supplier_file.sdf')
mols = [mol for mol in supplier if mol is not None]
In the above code, you need to replace 'supplier_file.sdf' with your SDF file.