How to approach and start talking to someone who intrigues me?
	
	
		Hello,
About two months ago, my relationship broke off after 4 years. She was my first and only until now, which leaves me quite unexperienced when it comes to approaching women. When I started to get a bit over my past relationship, I told myself I wouldn't actively go looking for someone else right away. However, when I see someone who intrigues me, one cannot just let the opportunity go to waste I would say? 
Anyway, already a few months ago, when I was still in a relationship, I noticed this girl who works at the same company as me, and who very often takes the same bus to work. I tend to see her almost every day when waiting for the bus to and from the workplace. At first, I just considered it a nice looking girl, but thought nothing more of it. However, now singleness has once again become a part of my life, I started to look at this girl in a slightly different way. Unfortunately, there are plenty of things stopping me from taking any action. So now I just go to work every day, not saying anything to her, but finding myself looking at her a lot of the time. I don't know what it is, but she intrigues me, and I would like to maybe talk to her and get to know her. 
What's stopping me however, are several things. First of all, I would have no clue how to open a conversation. This is something I already hardly do with 'normal' strangers, let alone with a girl I fancy. Where does one start? 
Secondly, how do I know she's available in the first place? I consider it would turn out quite awkward if I were to find out quickly she is already seeing someone, and can one just ask that on the spot anyway? 
Additionally, do I still have a chance at this? I have been sharing the same bus as her for quite a few months now. Do I still have a chance to suddenly start talking to her after all this time? 
As mentioned before, I told myself not to go looking for a girl, but something tells me I shouldn't just let an opportunity go to waste when it arises. So does anyone have any sound advice I could take into account? You are most welcome.
Regards