Please tell me, could I get epilepsy without a cause?

Not really . There is always a cause, as abnormal brain tissue is the culprit in all cases, but we doctors don't always easily uncover causation. Quite common is nerve injury via head trauma, but there are congenital malformations, blood vessel abnormalities, prior encephalitis or meningitis, or even toxic effects of meds or recreational drugs. Sudden stopping of alcohol may also be impactful.