lost my son's ipad want to see if i can another one?

Start here:

Locate a device in Find My on iPad - Apple Support

Here is Apple’s advice for lost or stolen devices:

If your iPhone, iPad or iPod touch is lost or stolen – Apple Support

Use the Find My app to locate a lost or stolen device – Apple Support

If the Find My iPad feature was enabled prior to it being “misplaced”, then if active, you would stand a good chance of locating it. 

However, if the feature was not activated prior to being misplaced - or the iPad has been inactive for more than 24 hours, the last known location will not be available - and the opportunity to use technical means to recover the iPad may have been lost.

You can get another by purchasing one. Apple does not

replace lost iPads for free.

If purchased via credit/debit card, the credit/debit card may offer some protection.

Contact the credit/debit card for details.

If you have homeowners/renters insurance, that may also offer some assistance.