Novel Schiff base ligand based on coumarin precursor was prepared by the condensation of 3-acetyl coumarin with 3-aminophenol. The newly synthesized Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) complexes were characterized by elemental analysis, molar conductance, spectroscopic techniques (IR,1H NMR, mass spectrometry, UV–Vis), and thermal (TG/DTG) to predict their structures. The results data displays octahedral complexes with 1M:1L ratio. The IR confirmed that the ligand coordinated to the metal ions in tridentate mode with ONO coordination sites. The complexes decomposed with three to five steps within the temperature range 30-900 C. Additionally, mass spectra of the ligand and its Cu(II) complex offer well matching data with calculated value. The molar conductivity values pointed out that the complexes were non electrolytes. Molecular optimization of prepared compositions at DFT/ LANL2DZ level, besides Molecular docking between Schiff base ligand (HL) and the receptors of breast Cancer were executed. Additionally, antibacterial activity has been evaluated against Streptococcus aureus and Escherichia coli. Additionally, fungicidal activity was screened in vitro against Aspergillus flavus and Candida albicans, using the disc diffusion method. The [Co(HL)Cl2.H2O].4H2O complex exhibits the highest antimicrobial effect against Streptococcus aureus with inhibition area 17mm, while against Escherichia coli it records 14mm, and 12mm against Candida albicans . The [Mn(L)Cl2.H2O].4H2O complex showing the lowest IC50 against human cancer (MCF-7 cells viability) with 22.2 µg/ml.