You don’t.

What about the copper tile

If real copper, isn't it going to patina (turn green-ish)? People put copper roofs outside and don't seal them. Check with the manufacturer for correct maintenance procedure.

What if I want the copper to stay shiny bright

I've never considered copper tiles, so I have no idea how they patina. Call the manufacturer tomorrow and/or post the tile brand/style/color here and we'll try to help you find the info.

What if I want the copper to stay shiny bright

Good luck. Metal Tile Care.

I'm using copper tiles (subway shape) as an accent in for my kitchen backsplash and the care isn't extraordinary - even the care instructions linked in cpartist's post just were to wash with normal cleansers and avoid harsh.

However my tiles are not bright shiny glossy copper - Do they make tiles with that kind of finish? I would check with manufacturer's instructions because the only copper I know of that remains shiny with no cleaning is fairly low use decorative items that have been lacquered in some way so they don't acquire a patina.

Here are my tiles

And here is a rendering of how the tiles will be used as an accent - as you can see there is nothing "shiny" about my kitchen :-) - that thing behind the sink that looks like the Statue of Liberty's head is not the design - it's just a placeholder for some kind of visual demarcation of the space :-)

If you want bright and shiny forever, then you should have chosen fake copper. You aren’t ever “sealing” teal copper to stop normal patina from forming. Not with anything homeowner grade, applied in the field. And certainly not with a tile sealer.

copper tiles will get brownish over time.