When will the season passes be available for next year?
The 2022 Season Pass signups were held in late February/early March, ahead of the River Market season:
I anticipate that the 2023 Season Pass signup process will follow a similar cycle, with applications appearing on the forum late February, 2023. It is generally a once/season process.
When will the Reserve booths be available again for sign ups?
The information you seek is in the Vendor Handbook here: