2002 Cadillac DeVille: I lost chip key

i lost my key with the chip in it n only have valet key how can i stsrt my car

Get another chipped key from the dealer. Heck, get 2.

Call a locksmith and ask them if they can make you a key without the chipped key.

Otherwise, you may have to have the car towed in and show the dealer your title so they can make you a new key.