You can pray with nail polish unless the nail polish contains a substance that prevents water from reaching what is beneath it.

If you cannot perform wudu, you can do taymmum. But if it is too difficult to do tayammum, then it is permissible to pray without wudu and tayammum.

This is how to perform tayammum: 1- Say Bismillah. 2- Strike the ground once with the palms of the hands. 3- Wipe the back of the right hand with the palm of the left, and the back of the left hand with the palm of the right. 4- Wipe the face with both hands. 5- Recite the same dua's that are recited after wudu.