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My assumption is that you are using PHP 7.4. Dat version does not support curly braces syntax. See this answer on stackexchange https://stackoverflow.com/questions/59158548/array-and-string-offset-access-syntax-with-curly-braces-is-deprecated . A downgrade to PHP 7.3 will help. That is also the highest supported version, see https://docs.civicrm.org/...
I think your missing some settings in your mysql configuration?
Taken from https://docs.civicrm.org/installation/en/latest/general/requirements/#mysql-configuration
I'm not 100% sure they will cure your issue but from how the storage engine/row lengths work in MySQL ...
I think you need to add an extra step or two. See https://docs.civicrm.org/sysadmin/en/latest/misc/switch-servers/ for more details
Deactivate old version and backup a copy of the CiviCRM database from the old install
Do your install in the new location and then activate with a new (empty database)
Rename the old Civi database as temp, restore the old ...