Custom gamemode thats just exploring maps?

Not sure if this is the right place but i figured id ask anyway. my little sister has autism (wild opener i know) and one of her favorite things to do is walk around game worlds and explore them, from giant open world rpg worlds to small pvp maps. shes obsessed with overwatches maps and wants to walk about them by herself. i have no idea how workshop works so idk if its possible, on the off chance it is does anyone know of any mode capable of that?

This should do, E8M9N.
Didn’t have the time to add many tools so if you really want something let me know and i’ll see what i can do.