What's the command to migrate images too?
Thanks guys for helping out! I figured it out and migrated all my images and files. Here's what I did for anyone who has the same problem:

I'm was using WAMP and WSL Ubuntu, I was setting the legacy--path incorrectly so my source_base_path was incorrect. I had to open up migrate_plus.migration.upgrade_d7_file.yml and used the correct path. Then I ran drush config-import to import the updated file and then ran the migrate.

Here's my file:

uuid: 2a4842a5-0869-4984-aaae-68d6c5814f5d
langcode: en
status: true
dependencies: {  }
id: upgrade_d7_file
class: Drupal\migrate\Plugin\Migration
field_plugin_method: null
cck_plugin_method: null
migration_tags:
  - 'Drupal 7'
  - Content
migration_group: migrate_drupal_7
label: 'Public files'
source:
  plugin: d7_file
  scheme: public
  constants:
    source_base_path: /mnt/c/wamp64/www/d7
process:
  fid:
    -
      plugin: get
      source: fid
  filename:
    -
      plugin: get
      source: filename
  source_full_path:
    -
      plugin: concat
      delimiter: /
      source:
        - constants/source_base_path
        - filepath
    -
      plugin: urlencode
  uri:
    -
      plugin: file_copy
      source:
        - '@source_full_path'
        - uri
  filemime:
    -
      plugin: get
      source: filemime
  status:
    -
      plugin: get
      source: status
  created:
    -
      plugin: get
      source: timestamp
  changed:
    -
      plugin: get
      source: timestamp
  uid:
    -
      plugin: get
      source: uid
destination:
  plugin: 'entity:file'
  source_base_path: /mnt/c/wamp64/www/d7/sites/default/files/
migration_dependencies:
  required: {  }
  optional: {  }