Can I ride my motorcycle in a parking lot legally?

If the public have access to the parking lot, you need insurance - which you won't get without a licence. You can be prosecuted for riding without insurance and that may involve impounding the bike depending on the law in your state.

If you're underage, you can only ride on private land and with the landowner's permission.

Technically no, not without the parking lot owner's permission. Public parking lots, such as the ones at Walmart and other businesses are private property, but mostly still governed by the same laws that govern driving on a real road.

So, if you can get the owner's permission and the lot is closed to the public, then you will be OK.

you can not ride on any public access land without a license. Ghost was right. If a cop approaches and ask you for a license because you look suspicious you could be in a little trouble. However there is a college close to where I live and I would take my bike there to practice wheelies. Never got in trouble and was never questioned. Not saying you should do it, but I am telling you my personal experience.

If you trailer or truck it to a parking lot with the 'owners permission', you can do it until someone ruins your fun one way or another.

However, just about any wartmart, grocery, or big box store is not going to give you permission.

Pick a Sunday morning when it's empty and there's no traffic. Watch out for the light poles. Stay in first gear for a while.

everyone is WRONG you can not get a ticket in any stores or business parking lot. Its private property.