Sorry for the long title.
Twenty years ago, I heard a prominent prophetic minister say that all believers need to be receiving signs, signals and tokens. He was confirming what I intuitively already believed. I do believe that God and His angels can do things in our natural realm to guide us, protect us, or to confirm things. However, I do not believe all things or even all coincidences are signs from God. My overarching belief about these things is that I do not follow signs. I might see signs and ponder them or consider if God is behind the coincidence.
Signs are confirmations. Spiritual signs are like signs on the road. They are neither the road nor the destination. But signs are a good thing.
Jesus had stern words for religious people who demanded a sign from him and ignored those who taunted him for signs when he was being crucified. However, Gideon was permitted to ask for a sign (Judges 6:17. Zechariah was rebuked for asking for more of a sign when God had already given him one (Luke 1:18).
So, there is nothing wrong with asking for a sign, but we must be careful and I would say, exercise faith in humility when doing so.