You are learning. There are a few key things to grasp when it comes to this stuff. It shouldn't be so complicated but it is. Once you learn the basics, it'll be easy.
When you set the place, you must also set the time. Don't ask her what works for her. Set the time. Lead the interaction. If she doesn't like the time, she can counter. It's up to you on whether to accept the counter but know in some cases, women will use this as a test of your strength. They will try to change times and venues on you to see if you have the balls to stand up to them and be willing to walk away if needed. This is one way some women test your neediness. A needy guy will always accept any counteroffer, be it time or place. A busy guy with lots of female options won't be so flexible because he is busy and simply doesn't have to!
Next mistake was allowing her to make the date tentative by saying she will "know what time she's free later." 80% of the time a girl does this, it will result in a flake. You are a busy successful guy and can't wait around for days to see if this girl can figure out when she will be able to meet. You aren't going to lock up you entire evening hoping she is free at some point. Any time a girl says any form of "I'll let you know," your response is always, "I'd love to meet you but I am busy and can't keep my schedule open. If you can't commit to a specific time now, just get back to me when you know your schedule becomes clear and we can try again then." You take the offer away. This demonstrates further value on your side and usually increases her interest accordingly. If she complains, just politely explain to her that you have friends and other things you would like to do that evening and can't put them all on hold while you wait for her to figure out when she's available. If she doesn't accept that, you ghost her because she has disqualified herself as a good prospect for you.
Also, generally when girls say, "I'll know what time I will be free later" or "let me get back to you", they are either trying to let you down gently and hope you just go away when they don't get back to you, or they are going to spend their week talking to as many more guys as they can and will select the best one to finally commit to at the end of the week. Can't really blame them for this but from your perspective, it's lame for a girl to expect you to just wait and see and hope. F-that. There are real world scenarios where a woman truly won't know exactly when she is free, but there is no reason she can't pick a time to commit to, even if it's later than planned, to ensure she will be free by then, or suggests another day/time that definitely is free. Think about it: could you offer that same thing to someone else? Of course you could. So why can't she?
Next mistake was the follow-up text. Ball was in her court before you sent that follow-up text. You wait to hear from her or she doesn't ever hear from you again.