Can someone explain to me how the molecules are reacting with eachother? All I get from the picture is that 1...

The word you're looking for is reaction Mechanism. Google diz: "Nucleophyllic Substitution Mechanisim 2° alkyl halide." Essentially what is happening is the bromine isn't gettin any pune tang from that whorish carbon, so he splits like K Fed, leaving the carbon unhappy and with a postive charge. This doesn't sit well for too long at all, so the amine compound which, with the help of the potassium salt, has become negatively charged and will satisfy the carbocat both sexually and financially. the point is the bromine had to break up with the diphenyl before amine swooped in and started supporting the fat bitch. In a more rapid SN2 rxn, a bond is broken/made all at once. there're no intermediates or lawyers or anything.

Thank you for this