You can't "upload" your wallet to Poloniex. You will need to get a deposit address on the "Balances" page and deposit your coins there.
That's why you shouldnt use a exchange as your main wallet btw. They control your coins after you deposited them at the exchange.
Is it wise to do this now sice it fairly up, or should i wait after the 1st?
Could anyone tell me how i do this?
I recommend you to keep your coins in a wallet you control the private keys. Always be careful with exchanges and never use them as a wallet if that's what you are planning to do. I believe we won't be getting a chain split in August, but it's not 100% safe yet.