I have two axolotl in their juvenile stage.I know that i could put some guppies in as food and tank decoration.What about tetra fishes?Is it possible for tetras to be in the same tank as the axolotls?will the tetras harm the axolotl's gills?
Tetras don't make a good choice. Their temperature requirements are quite different, being tropical. If you want cheaper fish look for feeder guppies. Feeder guppies are hardier, less expensive and extremely easy to bread as a food source.
In regards to vacation foods its better to just not feed your axolotl unless you are on an extremely long vacation (more than two weeks) or if the axolotl is a juvenile. Leaving fish in the tank can cause a lot of problems as the fish may die and foul the water which can easily lead to the death of your axolotl. If you need someone to feed your axolotl you should find someone you really trust to feed it.