If you're looking for a meeting place or a good stop around ½ or halfway between Syosset and Fairview, you can try Great Neck, NY, which is about half an hour west of Syosset, or about half an hour east of Fairview.
About ¼ or a fourth of the way, you can stop at Westbury, NY. This is about 14 minutes southwest of Syosset.
About ⅓ or a third of the way, you can stop at Mineola, NY. This is about 18 minutes southwest of Syosset.
About ⅔ or two thirds of the way, you can stop at Castle Hill Houses, NY. This is about half an hour west of Syosset, or about half an hour east of Fairview.
About ¾ or three fourths of the way, you can stop at Dyckman Houses, NY. This is almost an hour west of Syosset, or about 14 minutes northeast of Fairview.
If you drive straight through without stopping at all, the total distance is 35 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 60 minutes.