Choosing motors and motor mechanics

hello i am new to robotics i am trying to making a simple line follower using IR but with 4 wheels(i.e car) i don't know anything about mechanics.i am ok with electronics and programming but mechanics i love it but don't know how to use it.here is my problem

i want to make the front axle movable in my LFR car like how a normal can move its axle by steering.but in this i wanna use motor(i will control motor with microcontroller by getting values from IR reciever).How can i solve this mechanics i hav drawn several designs but i don't think it will work pease help me with this one

and should i use normal motors or servo motor and does servo motor has driver IC inside it?then why is everyone using it?

Yes servos have a driver IC

Yes servos have a driver IC inside so your microcontroller can easily control it, unlike a normal motor.

If you want steering like a real car you can copy a go cart, like in these photos. Alternatively you can settle for something similar to how a car steers by doing what Guibot did here. A 3rd option is to buy a cheap or 2nd hand RC car to hack.