Retiree seeks help with USB on Nexus7

[les64]

I am an active retiree but a total dinosaur when it comes to computers.
When the cold weather comes I travel overseas but want to stay in touch with relatives here through internet. 

In many countries Internet is often not easy and you are at the mercy of internet cafes but phone companies are introducing Internet access by purchasing a sim card with their USB 2.0 thumb drive and then money is added to the sim card as required.

I bought a Nexus7 with the intention of using wifi when available or buying a a sim card/thumb drive. As the Nexus only has a micro USB I assumed that I would need to buy an adapter to USB 2.0 and all would be well BUT the tablet does not recognize the USB 2.0 when I plug it in.
My question is is my assumption incorrect?  Is there any way to do what I want or did I buy the wrong Tablet?

Thanks for any help and please explain in simple terms.

[S.Prime]

You will need an OTG cable, available from Amazon or eBay. Just make sure that you find one that gets good reviews. Mine works with my wireless mouse and usb drives. I am betting that it will allow your tablet to recognize your USB device.

Sent from my Nexus 7 using Tapatalk