Squadrons onboard Ships -Noob

It's a matter of experience, redbeard.

For carriers, at level 1, you get 2 squadrons + 1 additional squadron for every two experience levels up to level 10. (3 at level 3, 4 at level 5, 5 at level 7, etc.)

You can buy your first two experience levels (and more with certain expensive research), but it costs a lot of money to do so.

A level 10 carrier with six squadrons is a pretty powerful aide to your little fleet.

-- Retro

If you open up one of the game data files you can see how many squadrons you get per level: ex. the tech capital battleship-
CommandPoints
StartValue 0.600000
ValueIncreasePerLevel 0.200000
This means that you will get one squadron at level 3 because (.6+.2+.2 =1) Then you would get one more at level 8 (.6+.2+.2+.2+.2+.2+.2+.2 =2)

Other ships also gain squads at levels. Kols are at 3 I think. Each race seems slightly different.