can anyone see where it says how many minis are in a squad

It'll be dependent on the squad. The Stormtrooper and Rebel Troopers both start at 4. You can see this explained in the Team Covenant video.

Depends on the type of squad... But for both the Rebel Troopers and Stormtroopers it's a base of 3 + 1 Leader, then you can add 1 more standard trooper, and 1 special weapon. That means 6 models max per squad for the two squad types we've seen so far.

Speederbikes start with two units and it doesn't look like you can add more.

The AT-RT only has 1 unit per squad and can't take any more.

Speeder bikes are 2 miniatures per squad. No more, no less.

You can also figure out how much the squad can expand. There seem to be two icons for that: regular trooper upgrade and heavy trooper upgrade. It seems like both the stormtrooper and rebel trooper squad start with 4 troopers and have 1 upgrade slot each for a regular and heavy trooper, giving us a squad max of 6 figs.

EDIT: oops ... or, in so many words, what VanorDM already said!