Introduced new fish with my other fish, i think they're fighting?

Neon tetras do best in groups of 3-6 or more. You cannot have them alone. He tried schooling with the zebras because tetras are a schooling fish. Guppies can be fin-nippers, so be careful. You also cannot keep guppies alone for the same reason. I suggest maybe 2-3 more tetras and 2-3 more guppies.