Welcome to the game Commander!

Probably the game is waiting for you to equip your gladiator, set your strategies and/or spend all your starting training points. If you can go to the equipment screen make sure you have a weapon and armour everywhere. Go to the strategy screen and make sure you set and save a strategy. Then go to the skills screen and spend your training points. If this still doesn't help let me know the name of your stable and I'll look into this further for you.

Good luck in the Pit!

-Nate-