Is it normal that weed doesnt work for me?

Two things:
1. Either you're not inhaling properly
2. Your dealer is fucking you over

I remember getting a friend high for his first time and it took A LOT of smoking to get it done. I had time to make all sorts of bongs and went through like a half a quarter or more before he finally felt the high. I smoked with him through it all and I was almost green by the end of it. My guess is that he didn't inhale properly.

After that he kept smoking for a while and it only took him the normal amount.

You might not have been inhaling properly...it takes some people a few tries to get the hang of it

Yes just like the one percent of people who's morphine receptors don't activate when given morphine the same can happen with marijuana. Unless someone is giving you hemp. Which acts almost like an anti-thc. If so get the real stuff and enjoy.