I am happy to hear you had a good experience connecting to Celonis.
Instead of trying to set up your own activity table from scratch, I would recommend you check out the Celonis App store. You find it by clicking on the Icon in the Top right-hand corner on the IBC start page.
In it you will find the out of the box process and analysis that Celonis offer.
The first step is to select a process, that uses the tables you have available, and to install it.
I would recommend you start with the Purchase-to-Pay process for SAP. As the tables you mention extracting (EKKO and EKPO) are the main ones you need for this process.
You can directly down load the process and connect it two your tables. It comes ready with all the scripts you need to generate an activity table containing all the usual Activities involved in P2P processes. If you want to make any custom modifications (such as additional activities specific to your organization) then feel free to contact us and we will help you add those.
The next step is to go to the App section of the App store and to install any analysis sheets for the P2P process that interest you.
Then you’re done, you are ready to start mining your first process!
I hope this answers your question,
Calandra (Celonis Data Science Team)