Is there a way I can pay monthly to get internet on my iPad when I am somewhere where this is not WiFi

If you have a cellular telephone as advanced as an iPhone, perhaps it can provide you a Hotspot capability. An IPhone could provide this capability if your iPhone's cellular carrier has provisioned your account to do this (may cost extra).

If you can create a Hotspot on a cellular telephone, then your iPad can connect to it using Wi-Fi. Here's more information.

Get help with Personal Hotspot on your iPhone, iPad, or iPod touch - Apple Support

You can if your iPad is a WiFi and Cellular model. There are a variety of options for short term/monthly usage. The following article has some information but offerings change frequently: https://www.imore.com/which-ipad-carrier-and-plan-should-you-get

You have to connect to something. If there is no wi-fi, your iPad would have to be connected to a carrier (assuming your iPad has phone capability). Otherwise, no.

Barry