The answer depends on whether you have hard or soft water, and on what the shower screen is made of,
If you have hard water you will need to use either household vinegar in warm water to dissolve the lime deposit left on the screen or acetic acid in warm water, then polish the screen with a dry tea towel or a sheet of newspaper. In other words as you do your windows.
If the screen is not made of glass, contact the seller and ask what it can be cleaned with, as vinegar, ascetic acid or salts of lemon may damage it.
In soft water areas, wiping the screen after use with a dry cloth should be sufficient. BUT everyone in the household needs to remember to do this!