location of sim card slot for iphone 4

If you can't find a SIM card slot on an iPhone 4, it is likely that you've got a CDMA only iPhone 4. They were produced for Verizon and Sprint once AT&T stopped being the exclusive iPhone carrier. If that's the case, the phone is essentially useless. I'm not sure it can even be activated on Sprint or Verizon anymore.

Between being out of the industry and rarely leaving the house, I'm not as up-to-date as I ought to be, especially on the TMobile/Sprint thing.

I know around the time I left Verizon, there was discussion of phones that were not LTE capable being dropped from the network. So, I suspect you're right.

It's on the right side of the phone.

Note that there was a version of the iPhone 4 sold for Verizon and Sprint. Those phones do NOT have SIM slots. They are CDMA only devices.

I'm fairly positive Verizon won't.

As for Sprint... well, I think you meant T-Mobile, now...

My understanding is they are going to completely shut down the Sprint network.

If you go to www.sprint.com, you're now redirected to the T-Mobile website. The deal is done, for better or worse.

High time. Sprint has been limping along for years.