Usually kittens open their eyes around 15 days old. They begin to move slightly earlier, but they should walk confidently around 3 weeks, on average.
On the other hand, I would advise you to think about having your cat sterilized, the shelters, charities and rescue centres are full because the feline overpopulation is enormous, and for her health too (uterus cancer etc. ...) and you also have the duty to identify the kittens before placing them :-)
If you place them, keep them with their mother until they are 3 months old, because they need to stay until that age to have all their mother's education (feline codes)