find command:https://www.howtouselinux.com/post/find-file-by-name-in-linux

Use find command, find all *.txt files but ignore foo.txt

find . -type f ( -iname "*.txt" ! -iname "foo.txt" )

To delete file add -delete or -exec your-delete-command-here option.

find . -type f ( -iname "*.txt" ! -iname "foo.txt" ) -delete

To select folder or dirs use -type d, in this example, find all folders and ignore foo and bar folder :

find . -type d ( ! -iname "foo" ! -iname "bar" )

To delete folders except foo and bar

find . -type d ( ! -iname "foo" ! -iname "bar" ) -execdir rm -rfv {} +

Be careful while deleting files and dirs.