Migrating from Magento 1.9.4 to Magento 2.4.1 – use the The Magento Migration Tool OR do it manually?

I would also prefer you to use the Data Migration Tool.
First, you need to install the data migration via Composer.

Ensure that you must update the location of the Data Migration Tool package in the composer.json file to make it work.

To do that,run the following commands:

composer config repositories.magento composer https://repo.magento.com
composer require magento/data-migration-tool:<version>

Then, migrate settings using Magento 2 Data Migration Tool and start migrating your store by using the following command:

php bin/magento migrate:data --reset <path to your config.xml>

If your store was up and running do checkout the best SEO practices as well.

  • Analyze Your Google Analytics
  • Analyze Your Google Search Console
  • Check Your High Performing Keywords
  • Fix The 404 Errors
  • Analyze Your Robots.txt File
  • Analyze Sitemap.xml File
  • Analyze Your Canonical Tags
  • Don’t Change Your Meta Tags

It’s not a complete process of migration but just a quick overview. I hope, it might be helpful for you.