"Pick up something" has different meanings:
To take hold of something and lift it up (It is also used for people)
She went over to the crying child and picked her up.
To receive an electronic signal, sound or picture
We were able to pick up the BBC World Service.
To get information or a skill by chance rather than by making a deliberate effort
Here's a tip I picked up from my mother.
She picked up Spanish when she was living in Mexico.
To identify or recognize something
Scientists can now pick up early signs of the disease.
To collect something from a place
I picked up my coat from the cleaners.
The last meaning is the one that applies in your case.
In your second sentence "pick up somebody" means "to go somewhere in your car and collect somebody who is waiting for you"; the OALD says that "pick up somebody" in that case is a synonym of collect.