If you're looking for a meeting place or a good stop around ½ or halfway between Copiague and Randallstown, you can try Philadelphia, PA, which is about 2 hours southwest of Copiague, or about 2 hours northeast of Randallstown.
About ¼ or a fourth of the way, you can stop at Newark, NJ. This is almost an hour west of Copiague.
About ⅓ or a third of the way, you can stop at New Brunswick, NJ. This is a little over 1 hour west of Copiague.
About ¾ or three fourths of the way, you can stop at Newark, DE. This is almost 3 hours southwest of Copiague, or about 1 hour east of Randallstown.
If you drive straight through without stopping at all, the total distance is 235 miles. The distances shown above don't include local roads to get into each town, so if you're planning a long road trip, make sure you factor in traffic and road conditions, rest stop breaks, and interesting detours along the way. If you're in a rush, you can do the trip with zero stops, and your total travel time would be around 3 hours, 55 minutes.