Librem 15 question

Do the Laptops come with Thunderbolt 3 and a SIM card reader?

I assume you mean the Librem 15? You can find the specs here.

Doesn’t look like there is a Thunderbolt or a SIM card reader.

No, I don’t think either. So you would need an adapter / dongle.

Did you actually want a SIM card reader? Or just somewhere to stick a SIM for integrated cellular communications? (which the Librem 15 doesn’t have)

It may help to specify what you would connect via Thunderbolt if you could.