First, you'll have to receive your citizenship certificate. When the oath ceremonies were in-person, you'd get the citizenship certificate on the same day as the ceremony. Now, since the ceremonies are online, the certificates will be mailed to you. Depending on your office and where you are located, it might take a few days to a few weeks to receive your citizenship certificate.
You can apply for a passport as soon as you receive the citizenship certificate. If you want it to be mailed out quickly, request the clerk at the end of the ceremony.
If you are looking to apply for an urgent passport or an express pickup, you'll need to request that and pay the extra fee.
Depending on the service you apply for, you could receive your passport by the end of next business day and up to 9 business days.
Good luck.