This is my personal suggestion, you should DYOR before investing in Cryptocurrency.
I would suggest you to divide $500 into four parts, it should be $100 into 3 and $200 into a single crypto . The top four Cryptocurrency that I would recommend to you is
1. Cardano - $100
2. BNB - $100
3. Litecoin - $100
4. Bitcoin - $200
You can change the amount as per your likes. I am not going to explain to you why I choose these cryptos, if you can check google, you will get your answer. I estimate within 2 to 3 months you should be easily able to make 2x of your investment. Remember as soon as you reach 2x individually or the total balance of $500 (which ever you reach first) cash out.
to be honest I'm not a fan of multi coins trading . I pick another coin with BTC and trade it. now I'm trading in BNB.
whats your opinion in XLM ?
XLM is a good option to invest .But i think the thread opener don't wanna invest on coin he just wanna scalping on the crypto market which is on of the way of trading but too risky .I think 500$ fund is enough fund for scalping but you need to have much knowledge behind that otherwise you can loose all of your invested money .