Can we trade older MacBook for the refurbished MacBook pro?

That is two questions:

1) can I trade in my older computer for cash or credit :

A: yes you can

2) can I buy a pristine, indistinguishable-from-new Apple refurbished computer from the Apple refurbished store?

A: yes you can.

Hi,

I don't know direct link or something, though try to contact Apple Support to ask about it.

https://support.apple.com

Hi,

You can.

Apple Trade In.

https://www.apple.com/shop/trade-in