Question:

"二分　ぐらい　まっすぐ　歩いて"
Trying to say "Walk straight for two minutes"

Answer:

excellent. If, however, you want to be a little more polite, you would say”二分　ぐらい　まっすぐ　歩いてください”　（Ａｄd”ください" after "歩いて”）