I replace my toilet now I smell waste in the restroom.
not enough info. Did any waste spill on floor when changing? has room been cleaned? Water in toilet bowl? Is water high enough in toilet bowl not to allow fumes to come up out of toilet stack drain since the toilet IS the pee trap [no pun intended] to prevent vapors from entering the room. Is there a sink/tub in same room? Are their traps full of water? Just a few thoughts off the top of my head.
also, you did use a new wax ring on new toilet and the toilet is sitting properly on floor drain fitting and bolted down?
Yes the room has been clean. There is a tub /sink in the same room. I water is low in the new toilet
Maybe caulking between the floor and the toilet?