Like any other investment existing, crypto is not 100% safe because it's associated with risk, so it's not guaranteed. However if you're looking for reliable and less risky crypto to invest in, then go for Bitcoin and hold for long term. But before doing that take time to learn about Bitcoin (or crypto in general) to become aware of what kind of investment it is and what to expect.

It's quite risky and not advisable. However, you're the only one who can decide about it after you gained knowledge and understand its nature. The basic rule is to only invest what you can afford to lose but if you're confident and has guts to take risk then it's up to you.