Wandering around aimlessly and ended up in a Church.?

I've been a Christian for several years, and I've never really gotten a chance to praise the Lords name within a Church and I've been having a really bad today. I got into a dispute with my mom, and I left the house because I was so upset. I sought out for a place to go, and as I wandered around in the rain I stumbled across a local church. I was speechless because I've never really taken the time to admire a church and I just thought to myself.. Why don't I go in? I reached for the handle and surprisingly it was unlocked. I walked into the entrance, and there was another door that lead into the big church room with all the seats. I stood behind the door staring through the glass in amazement. As I stood there, I heard an indistinct voice singing from across the church walls. Her voice traveled so loudly, and I heard somebody playing an organ. There appeared to have been no people within the Church except the maestro and the woman singing. I couldn't spot them through the glass window, and I wanted to enter into the church room so much but I just felt like maybe people weren't allowed to attend at the current time I was there. (10PM) I would like to go back there and pray amongst myself. Does anybody know if it's okay to just enter a church while there aren't any people around? I mean it wasn't locked so I guess its safe to say its available to the public at all hours. Am I wrong?..