According to Kathleen Bogle, the phrase hooking up is a slang term deemed unofficial and unpredictable due to the extended variation of its meaning.
What does it mean when someone says hook it up?
Hooking up is used to describe a sexual encounter (vaginal, anal, or oral sex) between two people who are not in a dating or serious relationship and do not expect anything further, their study says.
Do you want me to hook you up meaning?
It means to connect you to someone. You can hook up (for a date and sex), or someone could hook you up with a drug pusher, or some one could hook you up with a source for cheap disposable diapers, etc.