"if 2023 was the first year I did the backdoor conversation, the line 14 in 2023 form 8606=0. For 2024, should I put 0 as the line 2 on form 8606?"
Correct. Unless you have an adjustment to line 2 due to a rollover to a traditional IRA of after-tax funds from a qualified plan like a 401(k) or acquiring basis in traditional IRA contributions from a spouse due to divorce or due to the death of the spouse, line 2 of Form 8606 will be the amount from line 14 of the previously filed Form 8606. With no basis carrying forward from the previous year, the Form 8606 will have nothing carried over from any previously filed Form 8606.
