So yetserday I did a few modifications to my bike. I am no expert, but here's what I did.

-Firsty, I increased the height of my handle bars.
-Secondy, I increased the height of my seat.
-Thirdy, I found a bolt under my seat that would allow me to move it back and forth so I released it a bit and moved my seat as foward as I could (I own a Peugeot road bike from the 80s the the frame is kinda long).
-And Forthy, I played with the screws of the back derailer a bit.

Afterwards when I was biking back home I noticed that when I would let go of my handle bars that my bike would pull to the right. Very unpleasant, it doesn't have anything to do with me no being used to it, I can ride almost any bike from the first time I get on it with no hands ez pz even doding cracks at high speeds, taking turns driving really slow.

I have a feeling it might be from having moved the seat foward. But yeah sorry if this wasn't of much help. Thank you