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.