After 30 I changed my whole attitude towards woman and I learned 3 things:
1) Women can usually tell your intentions. If you are trying to evaluate them as a potential "girlfriend" candidate or doing an end-run to have your way with them, they will know, and they don't like it.
2) The concept of "girlfriend" can be dismissive and reductive. No one wants to be a "girlfriend", they want to be them, and to be loved for it, the label should come after.
3) Casual is key. My wife could tell I was interested when we first chatted, but also that I didn't want anything from her, I just liked having my little crush.
Don't look for a girlfriend like a target or a job interview, dive into people. Enjoy conversations and leave it at that. If you are lucky enough to repeatedly bump into the same person (without too obviously making it happen) then maybe you can have more than 1 good chat with them. But again, always imagine they can read your every thought. If you are thinking about how to get them to like you, or how to get them to be with you, they can tell. Just enjoy being with them in the moment.
I know this sounds hard, and I had zero luck with women myself until I did 2 things:
1) Accept that I would be alone forever and die that way
2) Just enjoyed individual conversations on their own merit, expecting our association to end when we parted.
The natural result of this (and my generally silly personality) was that I would be playful and friendly with complete strangers, I would have good conversations with anyone and when the time came to part, we parted without pressure or regret and with a few fun stories and memories. Because I never expected anything to go anywhere I wasn't nervous or pushy about it. I was just calm and casual, and when I did bump into the same attractive and fun woman a few times and figured "why not ask anyway" and asked out the secretary of one of our clients I had been locked in a long standing rib-poking revenge match with, she said yes. We didn't gel well in the end, but not too long after I met my now-wife. I never even asked her out. We just kept chatting and joking until we were a couple.
