What are the Latin words for machines and people? I want to use them as names of wireless networks. I am not sure how accurate Google translate is, but it suggests machinae and populo. Are those even close?
Machina is indeed a good translation for "machine". In plural it is machinae, so this translation is correct.
You have to be careful with the English word "people". If you refer to a people (where "people" is singular), the Latin word is populus. (The word populo is the singular dative or ablative of this word. Such inflected forms are not a good choice here in my opinion.) If you refer to to humans (where "people" is plural), the Latin word is homines. A single human is homo, and the plural is homines. In the context you give homines would be a better choice. If one network is for humans and the other for machines, then populus would be too grandiose.
In general, Google Translate is very unreliable with Latin. If you want to translate single words, I suggest using any of several online Latin dictionaries. After finding a list possible translations of your English word, I suggest also looking at the translations from Latin to English for each option; this can provide good insight to choosing the most suitable translation. If you have trouble finding the correct form, you can ask for help here. We also have a guide for asking translation questions at our meta.
Added from comments: If you want to say "for people/humans", then it is hominibus, and similarly "for machines" is machinis. In Latin one uses the dative case instead of a preposition here. But when it's used as a name, the context makes the intention clear, so I would say homines and hominibus work equally well. Just use machinae/homines or machinis/hominibus without mixing the two options, for consistency.
A suggestion : that instead of choosing a plural noun, perhaps a group noun would work well.
There is only one machine that forms anything like a network in classical Rome and that is the War Machine. There are several well-known units in the army; maniple ("a handful" platoon), ala (a wing, flank). But more machine-like are--
Testudo (literally 'tortoise') a manoeuvre against arrows and slingstones when shields were interlocked above the heads of the soldiers. And they might be using Aries (plural Arietes) a battering ram.
or, if you could borrow a term from Greek, which Romans often did (machina is a Greek word):
Phalanx a mass of men in heavy armour advancing in a solid block
... then your 'Men' would be a group name from civilian life.
Civitas a city-state populated by "cives".
Gens a clan.
But if you prefer to use plural nouns, my suggestions would be:
Viri ( plural of vir ) grown men, not children.
Molae (plural of mola ) mills.