I'm a beginner and i need help!

what type of needles should i use to begin with. i want to start with a scarf. should i use plain metal needles? plastic? what type of yarn should i use as well?

It takes some knitting practice to decided what type of needle material you like best.

I suggest maybe getting yourself some bamboo needles and smooth, light colored, worsted weight yarn. That will be the easiest to work with to learn. If you can’t find bamboo (or wood) then any other material is fine. Just practice.