My fish journey+ am I doing something wrong?

[IssyDizzy]

During the Christmas period I treated myself to a 10G freshwater tank (1st ever)
At first I didn't have a clue and:
Overfed
Didn't do a water change for a month
Put fish in after three days
Didn't gravel clean
Put to many fish in at once
But now I am loving the hobby and have filled my first with...
Two Molly's
Three neons
Three harlequins
They are happy and healthy and water parameters are perfect
One day I wake to find thirty babies swimming throughout my tank!
I put them in my breeder net

After a week the breeder looked awful when the fry rested the were swimming in their own waste

I didn't like this and wanted to help them

Yesterday I bought a beautiful looking 5G for the babies

I filled it with half of my established water and mixed the new sponges in the with old ones in water

Today I released seven in to see how they go however I am concerned

They can't find there food

The filter blows the poor things ( I will get a new one tommoz)

Plus it is beginning to get cloudy because of bacteria

I feel really harsh on them am I doing something wrong?

I will release a few more everyday

Also what are easy fish to breed out of these and how as this will be a breeder tank:

Guppy
Harliquen
Neon
Rummy nose
Glow light tetra
Molly