Line Follower 2 wheels vs 4 wheels

Hello! This is my first topic in this forum, so tell me if i write something wrong. I am currently making a few robots and one of them is a linefollower. I want to know if its better if its 2 wheeled or 4 wheeled, wheels will be fixed, what would be the pros, cons of each option?

wheels will be fixed

In what sense? Non-steerable? Or non-rotating? Non-rotating wheels are pretty much useless.

How do you intend to steer the robot, regardless of how many wheels it has?