Go into your working directory:
vagrant@homestead:~$ cd yourproject
Login to mysql:
vagrant@homestead:~/project-folder$ mysql --user=homestead --password=secret
Create database:
mysql> create database yourdatabasename;
Exit:
mysql> exit;
First export database you want to import into Homestead with PHPADMIN or similar tool into root folder of your application. Than type bellow:
vagrant@homestead:~/project-folder$ mysql --user=homestead --password=secret yourdatabasename < exported_database.sql