First time receiving a package at home, should I go downstairs to pick it up?

Hello! I have always ordered stuff to the konbini or the post office, but for the first time I’m having something delivered to my apartment.

I live on the 8th floor and I’m not sure whether it’s customary to go downstairs to pick up the package or to wait for the delivery person to come upstairs.

Also, I chose a specific timeslot (19:00-21:00), will the delivery definitely happen in that period for sure, or should I be home earlier just in case?

Sorry for the noob questions and thank you for reading/helping.