to the forum and to Keystone RVing. Here's hoping you enjoy your new to you Laredo.
As for the tile, I'm almost positive that trailer came standard with sheet vinyl, not tile, so what you're describing as "something a child put down" may well have been how it got installed LOL Carpet and vinyl are fairly easy to replace, just make sure you look carefully at how the carpet is installed around the slides. If you install it incorrectly, you may find that when the slide is retracted, the carpet gets pulled off the floor.
Again, welcome to RVing and to the forum.