With no traditional IRA already existing, you have no worries. Though I'd go and read up on it.

Pro rata rule isn't about double taxing. It's unexpectedly taxing you, because it causes you to accidentally leave some normal post tax money in the traditional IRA and bring some pre tax money with you into the Roth IRA, causing you to have extra unexpected "income".

It only affects post tax traditional IRA contributions, which only happens when you do a backdoor Roth IRA -- your contributions to a traditional IRA become post tax aka nondeductible at the same limit as the Roth contribution income limit . You don't have to worry about it with a Roth ladder or with mega backdoor Roth.

If you preemptively do a backdoor Roth IRA, when you're under that line, all the money in there is pre tax and it doesn't make a difference.

The guideline is mostly that you just need to have an empty traditional IRA by the end of the year if you did a backdoor Roth. The easiest way to do so is typically to do a reverse rollover into a 401k, which will only pull out the pre tax dollars, allowing you to retroactively select the post tax dollars for the conversion if you end up doing the backdoor Roth first, then the reverse rollover.

But that's all extra detail that it sounds like you don't need to know.

Just try and keep the contribution and conversion in the same year for simplicity.