Good for you, you're still young and quite eager to start investing. Regarding your question, the answer is popular coins, and there is nothing better than bitcoin itself. You can see history from year to year about the effects that occur after Halving on Bitcoin and other popular altcoin in Coinmarketcap. In addition to that investment, the potential remains, it's just that the risks faced are also getting bigger. If you just join the investment world, and want to start investing little by little, then start with the lowest risk, and that is a popular coin. However, you also need to understand the existing risks, because no matter how good the investment is, the risk will still be there.