Do you think Metallic Acrylic paint and oil paint would look nice together. Or Regular Acrilic paint with metallic acrylic paint. Or oil paint with regular acrylic paint?
And what do you think about islamic calligraphy? Do you think it looks nice? I need your opinion about it

If by Islamic calligraphy you mean religious, then it doesn't really matter if it looks nice as it has religious meaning. If you mean ARABIC, then yes, it is very beautiful and it can be distorted in exciting ways. Last year I went to the British Museum to see Middle Eastern artworks including Arabic calligraphy , both religious and secular. Yesterday I went to the British Library, to see the Sacred exhibition, displaying books and other artefacts by scribes from the Jewish, Christian and Muslim faiths. Wonderful. The previous answer is correct - don't mix oil and acrylic - acrylic would be a better medium for calligraphy, but be careful to rinse your brush and pen carefully.