If you choose "Ohlala" you leave it up to chance what happens on your date. If you don't want to leave it entirely to chance, you can provide some details in your request.
If you choose the combination "Dinner" or "Drinks" plus "Ohlala", you express a desire to meet in a bar and then go to a restaurant, leaving the end of the date completely open. If you just click on "Drinks", the date ends with the drinks you order. If you only choose "dinner", the date ends after eating together.