FTX has subaccounts to allow you to split up your positions if you want.
To manage your subaccounts, go to https://ftx.com/subaccounts. There you can create new subaccounts, switch which subaccount you're using, and transfer funds between subaccounts. You can also toggle which subaccount you're currently using by clicking on your profile name in the upper right hand corner and clicking 'Subaccounts'.
When using a subaccount, you can only trade with funds that have been moved to it. That means you can only trade on spot markets or convert using funds in the subaccount, and the collateral you post for futures trades is limited to that as well.
Similarly, if you get liquidated on a subaccount you'll only be able to lose whatever collateral you were storing on that subaccount. Margin requirements and position limits are also subaccount specific; any account leverage limits you set at https://ftx.com/profile will only apply to that subaccount.
Subaccounts are useful if you want to separate different strategies or traders; or if you want to isolate the margin and liquidation of a particular position from the rest of your book.