Apps will be a problem for upgrading. WARNING: June 1st is the Apps Migration Deadline for TrueNAS 24.04 and 23.10 - #56 by Roadrunr
I would work on making sure you have excellent backups of your data and document your system as detailed as possible. Apps will have to be recreated after working through why the most current versions of TrueNAS aren’t booting. You can try boot a Live Linux version to see if that works, at least. Browse the forum posts where people have boot and install problems as that may give you a few hints.