When should I move on and what's the workplace typically like?

I'm 18 and started my first job 2 months ago. I really like it, it's 4am-8am so I don't need to worry about customers or talking to people, and my co-workers are lovely, even the managers. I'd keep it forever if It weren't a part-time job, which really bums me out because If I could live on £500 a month, I would. But no one can move out with that, not even if I moved out with someone else. I'm just afraid that i'll get a full-time job and hate it, and the last thing I want is to miss my current job. I just want to know what work is typically like. I don't mind getting on with work, I do that anyway, but what are the managers usually like? Only recently I became good at my job, I was terrible before we got new equipment yet no one told me off, they just encouraged me, and I know not every manager or team leader is that nice. I don't want be in my mid twenties and still living with my mum, I want to move out at at least 23. But I don't know when to start looking for work?