"It's better to read something better suited to your level."
"It's better to read something at your level."
"It's better to read~" 「〜を読むといいよ」"It's good to read ~" や "it's enough to read~" も使えます。
"something at your level." 「自分のレベルに合ったもの」
"at your level" 「自分のレベルに合った」