Another quick, cheap way to make holes would be a nail & a hammer. You should be able to punch holes into the lid with the nail, just large enough to ventilate but not large enough for your snake to escape.

Welcome to the forum! The nightcrawlers can be found at Walmart, most of the snakes will eat those. You may have to cut them up if your snake is a baby. The fish from the supermarket is also a good idea, salmon, tilapia or trout. All of mine will eat salmon. I have never tried the silversides, so I'll have to try that next time. Silversides can be found at Petco. Mine also love the occasional live fish, so if you can find guppies, they work best.

Good luck with your new friend. What have you named her?