Things you need to know:

1. Don't do this if you want to make money. Those serious about this aren't doing it to make money. The value in these stocks right now isn't the monetary value but the strategic value.

This is not the time to buy if you want to make money. The people behind this have been very upfront that very few people stand to make money from this, many are expecting to lose it. This is about lots of people losing a little money strategically to ensure certain bad people lose a lot more of it. These stocks will eventually come back down. The questions are how fast, how hard, and what the final value will be. Only join in if you understand this.

2. Don't invest actual investment money. Certainly don't invest money that needs to go towards bills, etc. Invest your entertainment money. Money you would have spent on a game, on movies, on a kickstarter, etc. Money that's not going to make a difference on you being able to retire, or making the rent. Even the Asian millionaires jumping in are only risking money they can can afford to lose.

3. Don't buy in at the top price. I'm seeing on reddit people saying I just got GME for 350 I'm gonna be set when it hits x. No. You're probably not, and if that's what you think this is about, you're frankly an idiot that's very likely about to become a broke idiot. Even when the trending price is high, you can likely find shares being sold for less. Go for them instead. I don't pretend to know everything, but I would be surprised if GME goes much higher than it is now.

4. Again, don't jump on this if your intention is to make money.

Edit: I'm being told to add a legal disclaimer here, so yeah, this should be common sense, but I'm not a legal or financial expert so if you invest, you do so at your own risk.