Pick out or Pick over and Pick up?

To ‘Pick out’ something from a large group or a confusing background is to recognise it.
It’s difficult to pick out someone you know in a big crowd.

If you pick something out from a group, you choose it.
I want you to pick out the best application.

If you ‘pick out’ a tune on a musical instrument, you play it slowly, usually because you are just learning how to do it.
She picked out a tune on the piano.

To ‘Pick over’ is to sort through a number of things and select what you want.
He picked over the pile of peaches.


Pick up
learn
Children pick up languages more easily than adults.
catch an illness
I picked up the flu from somewhere.
lift something 
Pick up the phone.
charged, arrested or taken in for questioning by the police
If you're not careful, you'll be picked up for drink driving.
persuade someone to have sex
He went to the bar hoping to pick up a girl.
noticed
I picked up a lot of mistakes in your essay.
resumed
I picked up writing the letter where I left off.
get better or improve
This medicine will help you to pick up.
gained
The car picked up speed going down the hill.
pay
There was some heated discussion about who should pick up the bill.
collect someone in a car
Remember to pick up the children from school this afternoon.