Hi @Shruti1
Looks like you've got some hard time and I suspect your environment is fully on-premise or hybrid, can you donfirm?
If you're new on upgrading your Adobe Campaign instance and you're hybrid or on-prem deployment, I strongly suggest to engage Adobe Consulting Services to help you on the upgrade. If it is the 1st time and you're on your own, it's not the best fit for success the upgrade as any upgrade being not straight forward.
The online document provides information on the upgrade itself and how to prepare it
The 1st question will be which version of ACC are you on? depending of that, the upgrade might be a multi-stage upgrade.
By your different questions, you need Adobe Consulting Services to assist you in the upgrade activities and I will advise you to talk to your Adobe CSM to move it forward. The community will be able to help but not at the level of detail required for an upgrade end-to-end.
Sorry if it isn't the information you're looking for,
Thanks
