Is it possible if I come without any concept in my mind?
That is okay. You can discuss with our support team to find a concept which is suitable with your presentations later. We can do it by phone, Skype call, or Skype chat. We also have chat feature in our website which can facilitate the customer who comes to us and need to discuss something.
In the discussion, you will be served by the supporter and they will ask you some question or maybe also give suggestions. After you got the 1st draft, you also have 2 rounds for the revision and by take a look at your draft, it can bring you become closer to the concept that you really want.
You can also go to our example page (https://24slides.com/presentation-examples) and choose our presentation there that we can use as a reference to work on your project.