As the title suggest new to crypto, small investment of $500, which coins should I be looking to invest in?
Always make decisions while being backed by knowledge.
I could for example, turn your attention here:
https://bitcointalk.org/index.php?topic=1883902.0 It showed very good resistance to recent plummet, probably because of its "hodl" nature(profitable to hold). This will change at some point, so you will need to keep an eye on it.
Make sure to study this proposition carefully and don't act to swiftly.
Second thing is to diversify, split your investment in few parts or at least two, considering 500$ is not to much.
If you hesitate, go with BTC it looks like a good moment for buying.