the token doesn't work

While importing the Persons(s) through the static list you must select Fields to which you wish to map the value, if the field value is not auto-selected when you upload the .csv/.ssv/.tsv files. If you do not do so, it will either result in error (persons will not be imported or person data might get imported and mapped to the wrong fields.)

For the token part, you must have the field in the Instance. And you must select the token from the "drop down menu" for the campaigns/"Insert Token" option while inserting the token in the email. If you take these steps then token value will get populated.

My token doesn't work. When I imported the list, the tile "first name" and "last name" became "first" and "last" in the system.

Do you have custom String fields named "first" and "last" that you accidentally imported into? I don't understand your description.