Can you please go to the terracraft folder and look for a folder called "Logs"
Once there scroll all the way down to the last log and open it.
Then copy and paste the log files contents over here.
This will help determine the issue.
ALSO,
The terra craft server program is for hosting multiplayer servers. If you are looking to play single player all you need to do is:
Step 1: Go to the terracraft folder
Step 2: Double tap the "TerraCraft" program
Step 3: Once the program launches you will see an option menu
Step 4: Press "Singeplayer"
Step 5: You will then see the character selection
Step 6: Create a character by pressing the "Create" button
Step 7:Once you make a character you will be put back into the character menu
Step 8:In the character menu there should be the character you have created. Press on it
Step 9:Once you press on that you will be put in the world menu. Do the same as you did with the character
Final step: Just press on the world you have created and it should launch.
If you have any other questions feel free to comment them and ill try to respond when I am available.
Hope this helped!
-Yuki