Is it okay to shave or trim nails before Eid?

Assalamu alaikum! So we all know that during the first ten days of Dhul Hijjah, we shouldn't cut our hair or nails until after the sacrifice. But I'm a bit confused-does this ruling apply to everyone? My father is the one performing the Qurbani, not me. If I trim my nails or shave, would that be sinful? Please only answer if you're sure, jazakum Allahu khairan.