I just bought in a couple days ago, project looks awesome, really great idea. My coins are still currently in exchange (cryptopia). Do I need to do anything for upcoming hardfork?
If Cryptopia has their wallets with the software updated to the last release, all should be good. The version 1.3.0 that is compatible with the fork was released 6 months ago.
However, keeping your coins at an exchange is a terrible idea in general. Exchanges can crash, can be hacked, can run away with the money, and in all those scenarios you'll lose your coins. Just remember how many exchanges have crashed in the past, even the huge ones. Just remember what happened with MtGox, that back in time was the biggest exchange.
I honestly recommend you to keep all your coins in wallets that you control, not only Sia