Yes. Even if your availability falls outside the typical 9-5, don’t assume you won’t be able to find shifts. In fact, as a temporary PA, your ability to work unconventional hours could be a real benefit to your support of the CEO or MD, as their diaries may involve unconventional hours too.
Get email and contacts sorted as a first job. You’ll find yourself mailing or calling people continuously, so log everything and arrange folders so that you can find details fast.
Organisation is, of course, essential for a PA. That is effectively the job – organising your employer’s working day so they can make most efficient use of their time. But organisational skills without interpersonal skills won’t get you very far, because you need to be able to empathise with your boss and the people around you; you need to be able to engage in small talk with visitors and clients when the occasion requires; and you need to have the sort of active-listening skills that enable you to remember tiny details.