Hi Sherry, I used a product called AFM Grout Sealer that worked great for me. If you go to any hardware store though they'll have a selection.
You can purchase a sealer at any hardware or big box store. I would recommend the kind you paint on with a brush.
Hello. Grout sealer can be found at most hardware stores in the tile section.
This may help you, this is what we used https://www.pinterest.com/pin/804877764638007103/