There are no fees on deposits and withdrawals. FTX.US pays the withdrawal blockchain fees.
Once you've registered and KYC'd to the level you desire, to deposit, go to "Wallet" on the top menu.
Choose the asset you wish to Deposit. Click on that assets "Deposit" button, you'll see a pop up with the wallet address to input in the sending wallet address to deposit to your FTX.US wallet.
To Withdraw, go to "Wallet" on the top menu.
Choose the asset you wish to Withdraw. Click on that assets "Withdraw" button, you'll see a pop up to input the wallet address from the receiving wallet address and choose the amount to withdraw from your FTX.US wallet.