If you're looking for a meeting place or a good stop around ½ or halfway between Simi Valley and Glendale, CA, you can try Hickson, CA, which is about half an hour east of Simi Valley, or about half an hour northwest of Glendale, CA.
About ¼ or a fourth of the way, you can stop at Santa Susana Knolls, CA. This is about 9 minutes east of Simi Valley.
About ⅔ or two thirds of the way, you can stop at Sun Valley, CA. This is about half an hour east of Simi Valley, or about 13 minutes northwest of Glendale, CA.
About ¾ or three fourths of the way, you can stop at Burbank, CA. This is about half an hour east of Simi Valley, or about 9 minutes northwest of Glendale, CA.
If you drive straight through without stopping at all, the total distance is 36 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 40 minutes.