This is the 503rd most frequent Croatian word.
strani
"Strani" means "foreign" in English.
The word 'strani' is used here to describe 'jezik' (language), indicating it is foreign or not native to the speaker.
Učim strani jezik kako bih mogao putovati svijetom.
I am learning a foreign language so I can travel the world.
Here, 'strani' is used in genitive case 'strane' to indicate a specific side or vantage point, describing the location of the park relative to the river.
Na ovoj strani rijeke nalazi se park.
On this side of the river, there is a park.
In this context, 'po strani' is an idiomatic expression meaning to stand aside, suggesting staying out of activity or conflict.