Why is it so hard to talk to new people? I cant approach anyone and if anyone talks to me then i cant speak and just scratch my arms hard. Im afraid of people not liking me. Is anxi or am i just shy?

Don't reject yourself. You are projecting a bad end even before anything has happened. If you don't know what to say when they approach you, just ask questions about them, but avoid small talks. People like talking about stuff that make them happy and what they are proud of. Some people will ask you back, some not but it is ok. No one can be liked by everyone. You have to make sure you are in the right environment where you shares common interests with those people and it is a good start of a conversation. Don't be scared and give yourself a chance.