The most basic type of universal remote will have to already contain the codes for your model Vizio TV. The manual for the remote should list Vizio codes that you will need to enter and then try.
More advanced universal remotes such as the Logitech Harmony remotes have an online database of codes so the remote is programmed on your computer on their website.
If you have a cable or sat box many of those will have codes for TV power in them.
You can get a replacement remote...