What does " 발을 빼지 않다 " & " 발걸음을 맞추다" mean?
Please explain it for me and give me some situation when you use it.
Thank you so much !

Question

Answer

literally
발을 빼다 (take your feet out)
발걸음을 맞추다 (match your footsteps)
colloquially
발을 빼다 (running away and not taking responsibility) ~>발을 빼지 않다 will be responsible / confident 
발걸음을 맞추다 (level down with the other person / try to match the counterpart)