Migration Aix 7 to Redhat 8

I know that the file structure isn't the same from aix to redhat in regards to user accounts and groups. We are doing away with our old aix system and setting up a new RedHat 8 system but I have way too many users to try and setup all the users and create all new passwords. Is there any articles on how to accomplish this?
Thanks,

Welcome on board!

Any migration involves spending time to understand what can be done, the most important is what are you trying to do a port 1 for 1, or migrating to new architecture?
In the first case its your RH8 you will have to adapt so it complies to existing AIX, that means creating same filesystems structures and directories etc... and so you just copy from AIX to RH8 which has all same UID/GID groups etc, the only thing that will not match is passwords... creating a script that reads AIX users to recreate in RedHat isn't difficult to write, if you have like in AIX the possibility to add a generic password the same for all that the user HAS TO CHANGE at first connection , you are OK
You will have to go through the configs of some users in AIX in order to not miss some specialities like max open files, file size etc parameters

Good luck!