Once you've popped your pimple or the pimple has popped on it's own then the popped pimple is now an open wound so you should use some antibiotic ointment such as Neosporin on the popped pimple.
The Neosporin on the popped pimple will help keep infections away and help speed of the healing of the popped pimple.
You can also use hydrogen peroxide or Apple Cider Vinegar on the popped pimple to help it heal faster but first you should wash the area where the pimple is popped with some soap and water and then apply the apple cider vinegar, hydrogen peroxide and/or the Neosporin or other antibiotic ointment.