So my friend and I are trying to figure out the exact ruling on an issue. He has a creature out, then equips it with an equipment that grants Hexproof to the creature. Can I still destroy the equipment since it just gave it to the creature or does it give itself Hexproof also?
Assuming you mean Swiftfoot Boots, only the equipped creature has hexproof, not Swiftfoot Boots itself (C.R. 112.1a), so that Swiftfoot Boots can be the target of spells and abilities as normal (review C.R. 702.11b). Note, however, that a creature with hexproof can still be destroyed as normal, even though it can't be the target of some spells and abilities (compare C.R. 702.11b, hexproof on a permanent, with C.R. 702.12b, indestructible).
Hexproof and equpiment.