Your local store should have airlock gaskets or stoppers. Gaskets are nice as the hole doesn't have to be perfect. I'd swing by and find out exactly what they have to offer before drilling the holes. Sometimes, if you buy the airlocks & stoppers, they'll punch the holes for you even though you didn't buy the buckets & lids from them.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk