Using a throwaway coz my real account is too recognizable to some people..

Well, I'm a pretty shy guy and always think of myself like the nice dude who doesn't want to look like a creep. Hence, I basically have really never hit on women. Coupled with the fact that I'm generally non-assertive, I believe more in fate, which I now realise is bullshit. More so, I'm probably like a 5/10, but I can hold a conversation pretty well as I think I read quite a lot on different topics and am well-informed. But yeah, unfortunately, looks are visible on the first glance, the personality is not. I'm ok with that and am working to look fit and healthy.

So, reading all the stuff here I decided to do something about it and start with baby steps. Sorry for the wall of text. This is cathartic for me and I would really appreciate some advice.

1st encounter: I board the bus and there is a short, petite, blond girl who boards after me.. The bus is pretty full and we are squashed, standing for around 20 mins. Somehow, at a main stop, where like 80% of the people will definitely get off the bus, we get stuck near the door. Obviously we are pushed from all directions and she spots an empty seat and jumps to sit there and I sit next to her. I decide to man up and start chatting about how we were really in the wrong place.. she responds, all smiles. I had noticed that she had a university hoodie so asked her where she was off to. I am a student there as well and this gave me an opening. Of course, she said school and I acted surprised and said me too. She was now talking freely, discussing our courses and what not. We chatted for 10 mins before we had to get down and change the bus. Here's where I got really fucking awkward and basically got separated from her and sat at a different seat than her in the connecting bus. :( It ended fucking abruptly and I was cursing myself for a good 20 mins after that. Obviously, she went her way and I went mine. :( :(

2nd encounter: I approached the front desk on the 6th floor of my library for some assistance. There was this cute girl sitting there who was "swiveling" on her chair. Not sure if swiveling is the correct word. You know those chairs that you can rotate on? Just left to right, absentmindedly while resolving my issue. I decided to be bold, very unlike me, and said something along the lines of "You're having a little too much fun on that chair". She immediately broke into a big smile and seemed really receptive. Again, for an idiot like me, it got overwhelming and I just didn't follow up on it. I just nope'd out of there. :(

While I am happy with my baby steps, I would have really liked to use both these opportunities. How could I have made these work as they seemed like real good chances( assuming none of them had bfs)?

Any and all advice will help!