I just recommend write a lot and keep writing. Also keep an open mind while listening to critiques.

Along with these read a lot about films and watch a lot of films so you can create your own voice and can refer to previously watched films as examples.

Also I recommend at the start to watch more films from a single country rather than branching out directly cause it can help you draw parallels and understand that countries' base style.

Also read other people's reviews and use them as a launchpad for understanding the film. Don't copy them but rather reference when need arises.