Welcome to Android Central! Are you trying to send them via text or email? MMS (via texting) usually has an attachment filesize limit of 1.2 MB, so almost all videos will be too big. Gmail has a 25 MB limit, so a somewhat long video may also be too big. You should upload the video to YouTube or your Google Photos in the cloud, then share the link privately with the recipient. You should also be able to upload it to your Google Drive, unless you're out of Drive space.