If you're looking for a meeting place or a good stop around ½ or halfway between San Francisco and Livermore, you can try Hayward, CA, which is about half an hour east of San Francisco, or about half an hour west of Livermore.
About ⅓ or a third of the way, you can stop at Piedmont, CA. This is about 16 minutes east of San Francisco.
About ⅔ or two thirds of the way, you can stop at Fairview, CA. This is about half an hour east of San Francisco, or about 16 minutes west of Livermore.
About ¾ or three fourths of the way, you can stop at Dublin, CA. This is about half an hour east of San Francisco, or about 14 minutes west of Livermore.
If you drive straight through without stopping at all, the total distance is 44 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 51 minutes.