To sign up for a Vimeo account, click here.
To use YouTube, you need a Google Account. If you don't have a Google Account, click here to sign up. Otherwise, click here to login.
Once you have a YouTube or Vimeo account, you can add a video to your website with the video block.
Please note that as these are third-party integrations that there may be a cost associated with their services depending on the level of service you require from them.