[@ayzrules]

Some things to know about the 1990s:

- Bill Clinton was president for most of it (and pretty much all of the Animorphs run.)
- The Twin Towers were still standing, and we had little to do with the Middle East after the Persian Gulf war in 1991.
- Japan was still a close economic rival of the US, although they were slipping behind us. China was way behind where it is now.
- The late 1990s saw a fad for "dark" and "edgy" characters, such as Blade and Neo from "The Matrix."
- There was a second wave of Japanese cultural imports into the USA. Power Rangers, Pokemon, and Dragonball (this was mostly Dragonball Z, few people watched the original Dragonball, and Dragonball Super wasn't around at the time. Not sure about Dragonball GT, which isn't canon anymore IIRC) were way more popular then, and anime wasn't usually (fairly or unfairly) associated with perversion. 
- The internet was a novelty, dial-up internet was standard, 3D video games were geometrical and blocky, and Yahoo was the biggest search engine. Google was in its infancy. And some people still called the internet "the information superhighway." 
- Songs like "Macarena" and bands like "The Backstreet Boys" were big.
- "Cool" meant skateboards, dark sunglasses, and showing disrespect to authority figures. Wearing a baseball cap backwards was also a thing. And pogs were around for a few years. As were hand-held pixelated electronic "pets." 
- People attacked video games for causing violence (they don't!). Today, they attack video games for being sexist (they're not!)
- Spider-Man and Batman were the biggest comics. Few people even imagined a movie about Iron Man, let alone the Guardians of the Galaxy.
- Rap was around back then, but it was different from today. Hard to describe it. Just listen to 90s rap to what we have today and you'll hear the difference.
- Radioshack was still around and was quite popular.
- Tesla wasn't around, so don't mention it. SUVs were popular then as now, as was the Hummer in some circles, which isn't around today.
- Also keep in mind that social media was in its infancy, and that no one had a smartphone. In fact, cell phones were rare in the 1990s until the last year or two. 
- Nintendo, Sega, and (later) Sony made video game consoles. The Nintendo 64 and Playstation were the most popular, and Xbox wasn't around. Sega had a few consoles (including the Genesis), but Sega exited the console market in the early 2000s. 
- Computers were usually quite large, slow, expensive, and there were few laptops. They also had very little memory, so don't mention anything with a terabyte of data unless it is a supercomputer or something. The biggest operating systems were Windows 95 and 98. Don't mention Apple unless you want to say it was a washed-up has-been, which it was between the early 1990s and early 2000s. Now it is back. Dell was the biggest PC company back then.   
- Animated movies were almost all 2D, although Pixar was starting to make 3D films back then. 
- Movies started to use special effects more, starting with Terminator 2, and especially after Jurassic Park. For a while, big movies were little more than a way to show off the effects, but they got better eventually. 
- Titanic was the biggest movie of the 1990s, but that came late in the decade.
- People used VHS tapes (and maybe Betamax?) and laserdiscs, and later transitioned to DVDs. Look up anything you don't get.
- Finally, the Walkman was not quite the same in the 1990s as it was in the 1980s. If you've seen Guardians of the Galaxy, you will notice that Star-Lord has a tape cassette in the walkman. In the 1990s, this was replaced with a CD (compact disk), which (if I have to say it) is basically a blu-ray.