"Coins" aren't a thing, so there's nothing to be tainted, per-se. However, yes - if an address that ordered a murder sends you a lot of btc, expect someone to come by and discuss it.
Also, the waters are muddied now (intentionally), in a similar way to how every piece of American cash is rumored to have traces of cocaine on it. The theory is that the more this implicates everyone, the less it implicates anyone.
But, Bitcoin is not an investment.
First, nothing you don't understand is ever an investment for you. If you don't know mining and I do, I'm investing by buying shares in a mine whereas you're gambling by doing it. (For instance, if you don't know, and really understand, why bitcoin tends to be used in a manner where you empty the balance from one address, sending some to the intended recipient, and the leftovers to yourself at a new address, then you're not ready to invest.)
Second, it functions as a store of wealth not capital. Its gains are partly from other currencies devaluing around it, not it being used to create more goods the way buying a piece of capital (shares in a manufacturing company) would.
That said, if you do any gambling (lottery tickets) you might as well put that into bitcoin, you at least might get something back.
Yeah I briefly read about mining and how it's not worth it anymore unless you join a group to mine with.
I don't know, I'm not even able to open up bank accounts anymore/at the moment so I have different accounts whether prepaid or through job provided bank accounts or PayPal business account.
Yeap I'm not in a good place at the moment.
Thanks for the information.
In that case, where you don't have false goals of runaway success or anything, and aren't gambling the farm on it, yeah you should throw a few bucks into it. If you read up on what the differences between currencies are and how that's likely to impact survivability, you'll be able to pick fairly well.
BTC, Ethereum, and Monero look good, but do your own research. Scams abound.
The most critical thing to remember is that if your currency is "in an exchange" it might as well not be yours. Funds only become yours, meaningfully, when transferred to an address whose keys you generated and which have never been online on an insecure device.
Ideally repurpose an old phone for a wallet and keep it in airplane mode. You can browse the chain with your regular phone, including monitoring incoming transactions, all you won't be able to do is sign an outgoing transaction. Then you either turn on the wallet-phone's connection when it's safe, or implement a paper-wallet system between the online and wallet phones.
That's overkill for what you'll probably put in right away, but good practice.