How do I change my iPad from 5.0GHz to 2.4GHz?

it's up to your wifi router if 5Ghz is enabled, and it is also up to your router if it's 2.4Ghz and 5Ghz bands are bridged so it would be transparent for the iPad and the non apple product that they were connected to each their frequency band.

Update

HiHello Sir update please

You don't need to. Your iPad will find and use whichever band has the best connection. If there is only 2.4GHz then your iPad will connect to 2.4GHz.