So, this past weekend I hooked up with this girl I met at a bar a couple weeks ago. I thought everything was well and stuff. We did hookup, but later on she admitted that I don't have "the game" and I'm a nice guy, and "that's okay".

I guess I was a bit upset at myself. I was never good at non-monogomous casual hookups or FWB type of setups. All my past intimate relationships were serious and semi-serious long term relationships. Now that I'm recently single after a very emotional 3 year relationship, I'd like to step my "game" and not be the "nice guy" anymore,. Can somebody guide me on how to develop this "game"? Any thoughts would be appreciated. Cheers!

Edit 1: It's worth mentioning I'm a 27M, working in tech.