*Warning: must be mature to understand the following concepts*
I see first dates as a sort of interview. The goal is to find out more about the person and see if you click. If you're serious and you're looking for a relationship, your questions should show that, and you should be able to engage in deeper conversations rather than stick to the surface basics. If you've had enough of the dating BS that's happening nowadays, then stop asking BS questions and start being straightforward. Here are some good examples of some tougher questions that will actually be useful:
1) Ask more details about what they do in life. You most likely already know what their job is, but ask more detailed questions about their schedules, hours, and travel requirements in order to figure out where and how you would fit in the person's life.
2) Ask when their last relationship was. Like I've mentioned before, being fresh out of a breakup is a huge red flag. Here is your chance to see if you're just the rebound, or if the person seems genuinely ready to meet someone.
3) Ask what were the most common reasons for previous breakups. Here's a good opportunity for the other person to express some of their flaws. You'll see if they can admit if they're wrong, which I find to be a VERY important trait to have in a relationship.
4) Ask why they think they are single. If their reply is something along the lines of "they want to be/they love the single life", they are 100% planning on remaining single after your date.
5) Ask about family and friends. And hint to meeting them. If you're interested in the person, let them know you are by also showing interest in the important people in their life. Tip: avoid sounding creepy by making a joke like "so when do I get to meet the parents" and then add something along the lines of "no but seriously they sound like great people and I would love to meet them someday." If they don't appreciate that, they're either not interested or not looking for more than a hook up.
6) Ask if they're just looking for a hook up. Instead of asking "what they're looking for" and receiving a bullshit answer they've rehearsed 50 times, be straight up. Chances are they'll be too in shock to think of a smooth BS answer. You'll be able to tell right away just by their reaction ;)
7) Ask to plan a second date. Right on the spot. If you're interested and the date went well, why wait a few days or weeks to plan another date? Tell them you had a great time and you think you both shouldn't waste time and just plan a second date right away. I feel like a big reason why dating often ends after the first date is because people wait too long and end up losing interest with time. Keep the person interested by seeing them more often right from the start.