I am very disappointed in Apple. My recently bought iPod Touch 4g cannot download most apps including Facebook and Messenger because "I need ios 7 and above" to download it. I need to download these 2 apps. Please help?

Hate to break it to you, but your 4th gen touch is probably 3 years old and a discontinued model. The current models are the 5th and 6th gen.

You bought an old model with an old iOS operating system. (the current is iOS8 with 9 due out in a month or three, you are running 6)

If you've synced your touch with your computer you can try to use iTunes to download the apps, which may allow you to get older versions of the apps, if they are still available.

or, I have no idea where you bought your touch but you could always consider returning it and getting a newer model that will have a longer compatibility.

The 4G was first introduced on Sept 1, 2010. That make it over 5 years old

Install the latest compatible version of an app on an earlier version of iOS or OS X - Apple Support