Question

How do we calculate bond order , bond enthalpy bond angle , bond length

Answer 1

bond enthalpy 
it is the strength of a chemical bond
it is the energy required to  break a bond  

bond order
it is the number of bonds between two atom

bond angle
the angle between the orbital containing bonding electron pairs around central nuclei of atom 

bond length
it is the equillibrium of inter nuclei separation distance of the bonded atoms in a molecule