Usage patterns
新鮮な〈物〉fresh ~ (food, air, etc.)
I bought fresh fish at the market.
新鮮な空気fresh air
I breathed fresh air on top of the mountain.
新鮮さを保つto keep something fresh
You keep vegetables fresh in the refrigerator.
新鮮に感じるto feel fresh/new (about an experience or idea)
My first trip abroad felt very fresh and new to me.