Its only just hitting me that I'm going to an entirely new place, with new people. I have no idea what I'm going to do...

Most people are friendly, you will always make friends. I went to 4 different schools and 1 in south america.. trust me from personal experience you will always make friends. Take the initiative.
Some tips i found useful.
I remember the first day in year 11 at my new school, i walked in late and made a beeline to a table with another person on it. It is so awkward to sit by yourself.. because then its hard for others to approach you. If there's a spare seat in your class, ask if u can sit there, sometimes its best to sit next to the same sex, as it will send different signals in different scenarios. Dont ask the same old questions because it gets monotonous very quickly. And do not be afraid of speaking
This is how my first conversation in year 11 went:
I walk in late, i make a beeline to a guy who is sitting by himself.
Me: Hey dude, this table free?
Him: Yeah man
Me: Thanks dude, im darth_pepe
Him: Hi im him
Me: Shits hard to find man, lost on the first day lmao
Him: Yeah man.. im new too
Me: Ah cool, where were u from?
Him.. ah from ..
Trust me, the more you talk to people the easier it gets! It also helps with public speaking! Im at monash too btw so if u kick back in the library holler at me bro
edit:
I forgot to say:
If anyone plays dota2 or csgo, let me know we can go for a game