Well These are the fundamentals which you must always remember
here are the 3 basic Bonds but there are a lot more to learn:
Here Both oxygen atoms have 6 electrons in their outer shell.
They each give 1 electron to be shared and they get their completer octet in their final shell.
Metallic bonding is the electromagnetic interaction between delocalized electrons, called conduction electrons, gathered in an "electron sea", and the metallic nuclei within metals.
This what gives electrons their properties like ductility