RNGs?

In regards to what kind of RNG to use, the right answer is almost always the one built into the programming language you’re using. The vast majority of use-cases do not require anything more than this. Cases which do need more than this are things like lotteries and encryption, where predictability has obvious consequences. Unless you’re working on slot machines which need to satisfy very strict laws, seeding the standard library function with the current time is the way to go.