The invisibility skill that the imp can use reads like this:
Invisibility. The imp magically becomes invisible until it attacks or
until he finishes his concentration (as if concentrating on a spell). Any
the team that uses or carries the imp is invisible to him.
Your character is not a team, so the imp cannot make them invisible too. However, if you hid inside a bag and the imp carried it, it would become invisible and you would be effectively invisible as long as you remained inside it.
As Tiggerous pointed out, the default wizards cannot have a familiar imp. The Find Family spell says:
You get the service of a family member, a spirit that takes the animal form you choose: bat, cat, crab, frog (toad), hawk, lizard, octopus, owl, poisonous snake, fish (quipper), rat, crow, sea horse , spider or weasel. Appearing in an unoccupied space within reach, the family member has the statistics of the chosen form, although it is a heavenly, a demon or a demon (of choice) instead of a beast.
Imps aren't on that list and they're not beasts either.