Regardless of whether anything will come up in Enhanced Disclosure, you still have to declare your caution. If your uni later finds about the incidence which you haven't declared, expect to be kicked off the course immediately. When you declare, it's up to your uni to decide whether to confirm your offer. If it's referred to their criminal record committee, you will get a chance to make a submission, giving mitigating circumstances, testimonies from character witnesses, that you take full responsibility for your past action, how you've learnt from it and will never happen again and are prepared to move on. It may not be enough, as physical assault is taken very seriously (and a teacher who assaults pupils may be jailed and sacked). Remember the training provider will get the blame if they recruit unsuitable trainees, and schools have a duty of care towards their pupils. How long ago was it?