Invest in Docking Computers, and locating entrances is irrelevant...
Using "fast dock" at non-main stations results in the slow docking sequence running, you don't want to watch that every time. Moreover, it can result in BOOM press space, e.g. try at a deep space dredger. IIRC I also BOOM pressed space when doing that at a main station once. Watch and cease immediately if you come too close to something. Other times it results in the sequence failing and you drifting away into space. It worked at space bars however so far for me, so you can use it to locate the dock. You don't get to see much of the bar however.
Using "fast dock" at main stations is safe, but costs 20 ingame minutes which you may not want to spend.
warning sound if a missile is inbound: Missile warning