Red eye tetras are fin nippers and might go after the Corydoras because they get bored easily and you only have 3 of them. Personally, I would get rid of the red eye tetras.
The glow in the dark tetras could be black widow/ skirt tetras, which are also fin nippers. however, you have 9 of them and that will help keep them occupied.
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Corydoras do best on sand substrates or small smooth gravel substrates. Take some gravel and rub it against the palm of your hand, if it scratches your skin it is too sharp for the catfish.
Corydoras prefer live and frozen (but defrosted) foods. Most will take bottom feeding pellets. You feed them once a day, usually in the evening an hour or so after the lights have been turned off. Some will come out during the day and eat then, but others prefer to feed at night. Try them during the day and at night and see what happens. But don't over feed them. Any uneaten food should be removed after 5-10 minutes, unless it's live food like daphnia or blackworms, these can stay in the tank until eaten or sucked up by the filter.
Have some plants or driftwood in the tank to provide a shelter during the day.
Keep the water clean and do regular gravel cleaning, and away you go.