Things to practise as a newbie:
-Patience
-Car control (knowing where limit is and ability to keep car under control in all racing situations, meaning understanding that speed when racing close to other car is not same as when you hotlap)
-Patience
-Racing lines and rules part considering racing line
-Patience
-Understanding that race is lost in 1st corner, but never won
-Did I mention Patience?
Now why there is patience mentioned so many times is that it is what helps you learn and win races.
Take autocross arena and make small slalom track from cones, start practising car control and handling there, slide a bit and come familiar to how car reacts, this will teach you skills you need when avoiding spinning cars or some other situation you come up when racing.
Then when you can keep car under control, start going to servers, be friendly and you can even say that you are new, when racing keep distance in first runs and don't even try to win, just race along and see how other brake etc, just avoid accidents at all cost.
You will find some nice guys from servers and some will teach you more, help improve times etc.
Well, there is a start I would recommend