I've been looking but I can't find them :/

Actually I just found one, its through the door behind the counter of the cafe

Secret Room 1: Go into the door behind the counter at the Cafe. Clip through it if you have to.
Secret Room 2: Head down the first set of stairs in the Pools area. Look straight ahead and enter no clip mode (V or type "noclip" in the console). Clip through the wall and you will see a TV, a couch, and a table with fruit and a bottle on it. All of these objects are on a platform and surrounded by water. I don't know how to access this area without using noclip mode.

secret room 2 as bwalker5 said has an activation trigger on one of the cafe table legs near the counter on the right side

There is one in the bathroom but im not sure wether that counts as hidden. The table on the right of the counter has a trigger and you press E on the table leg and it teleports you to the hidden pool