If $0 in current traditional/simple IRAs, but put $ in simple IRA later, can I backdoor now based on $0 in current accounts (ie. later simple IRA $ will not impact)?

currently, there is no money in traditional and simple IRAs.  If I contribute $ to the traditional IRA and backdoor convert to Roth right away, then start to contribute to the simple IRA, when it comes to tax filing next year, would I need to take into consideration the money in the simple IRA or still use the $0 at the time of the conversion?  Thanks.

Richard