Request you suggest answers for below questions

[Nikhil Futane]

1. What primary precautions we have to take if  we Upgrade JIRA Software to 8.13.0 software version without impacting existing projects/boards .

2. Also, What points we can consider to modify exiting Issue types, workflows, screens, schemas, fields, permission schemas and security groups required for managing projects.

[Nic Brough -Adaptavist-]

1. None.  You will always be affecting the existing boards and projects, it's a new version of the software.  Of course, you should always have a backup and a roll-back plan in case things go wrong, but you can't expect everything to stay the same when you're changing it.
2. I don't understand what you are looking for here.  If you're modifying config, you're modifying it.  What "points" are you asking for?