18.0.0 introduced execution environments, and 14.0.0 is 3 years old, So ancient by Tech terms.
there are database migrations and changes that happen version to version. You are better off doing side by side, an export, of what you can, and then use the infra.controller_configuration collection to put those pieces in place on the new one(it should be compatible with the old export).
There is no good answer, just hard work. Everything else could be transferred by hand, and credential values are never exportable.