It is essential to deepen your understanding of strategy and to become familiar with the characteristics of the Premier League
「戦術理解を深めプレミアリーグの特性にも慣れる必要がある。」は英語で「It is essential to deepen your understanding of strategy and to become familiar with the characteristics of the Premier League」という表現が良いと思います。
戦術理解を深めーDeepen (your) understanding of tactics/To cultivate a better understanding of strategy
プレミアリーグの特性にも慣れるーTo grow accustomed to/To get used to/To become familiar with The characteristics of the Premier League