Of all the small pets, gerbils are perhaps the most naturally tame and easy to handle. They are inquisitive too, so it should be perfectly possible to handle a gerbil within a day or two of taking it home.
The correct way to pick up a gerbil is to let it hop onto your open hand rather than trying to grab or grasp it from above. Eventually your gerbils will become so tame that they will hop onto your hand - especially if rewarded with some sunflower seeds.
Let your gerbils come to you - if you reach out to grab them they might get frightened
How not to pick up a gerbil
In the wild, birds are their natural predators, so they are very wary of a hand coming down from above to grab them.
Although their tails might look strong, they are actually quite fragile and can be easily damaged. Never grab a gerbil by its tail, other than to gently but firmly hold the point where the tail joins the body. Instead get both your hands under the body and lift out whilst holding the base of the tail between two of your fingers to stop the gerbil leaping off if startled. A tail can be easily damaged if grabbed, causing the very tip to come off or even more of the tail. This is a defence mechanism and in the wild would allow the gerbil to escape from a predator. The tail never re-grows and in most cases heals without any Veterinary intervention. However if you are in any doubt about any injuries to the tail then it is best to get the gerbil examined by a Vet who will be able to prescribe antibiotics as necessary.