A squeaky noise is a common problem on shower doors.
Shower door hinge noise.
When the shower door squeaks at the hinge it may mean the hinge is loose.
That allows water to escape from the shower enclosure onto the floor.
If you wish to match the hinges to the door color 1 see if they sell hinge kits in your chosen color they account for spacing when they paint to prevent squeaks or 2 take the hinge apart apply a thin coat of oil based paint it will last longer than acrylic and lubricate well.
More often it means the hinge is dirty rusty or corroded so that the hinge does not move freely.
A slippery floor can easily cause you to fall and sustain serious injuries.
Let us know what other questions you have about shower doors or other.
It is often caused by dirt or rust on the door hinges.
The door fails to latch properly when it is closed.