Why does my tolerance seem high for only my second time drinking?

I am 21F, and I have only drank twice in my life. The first time was back in June, where I didn’t each much that day. I had 2.5 shots of 40% vodka and 1 twisted tea within a half an hour window. For a good 30 minutes, I couldn’t keep my head up straight, I was squinting, and I was nauseous, and I just felt like my emotions were neutral. After that point, though, I was a dizzy for the rest of the night with absolutely no other impairments (I can recall every event from that night, I could walk straight, I didn’t feel overly giggly or any other changes to my usual norm).

The second time was at the beginning of September. I had eaten a decent amount that day, but over the span of an hour, I had 2.5 shots of 35% vodka and 2.5 twisted teas. My “high” was just a very dull feeling, which faded off into dizziness for the rest of the night.

Am I simply just not understanding how alcohol works yet? Is this normal and expected? All I wanted both times was to have that laughing/giggly/happy feeling but I didn’t experience that both times, and especially the second time, I did not feel much. I would consider myself curvy (neither skinny or “big”), so I knew I would have a higher tolerance than my friends eventually, but not this soon.

Please help because I want to have fun next time without under-doing it or over-doing it