Hello,
You can use software like EaseUS Todo Backup, AOMEI Backupper, Clonezilla, RescueZilla, and Macrium to back up your files to a flash drive.
You can then restore the backup to the computer if needed by using the respective option to do so in the app.
Make sure that your flash drive is has a storage capacity that is greater than or equal to the capacity of the disk you have in your laptop.
Hope this helps.