How much is needed to get an apartment?

I'm 22 and tired of living in my parents house so I'm looking for a job right now so I can save money and move out. I've been applying literally everyday. I have an interview Thursday and I hope I get the job. Where I live most apartments even for a one bedroom are like 900 a month and a two bedroom is about 1200.

I highly doubt I will be able to afford an apartment alone so my plan is finding a roommate and sharing the cost of rent. If I plan to pay 600 a month maximum for rent how much money do you think I need to save overall before I can start looking? I'm really inexperienced with this type of thing, I've tried to move out before but it was unsuccessful so I'm trying to be independent and prove to my family I can do this.

For clarification I live in Oregon in the Portland metro area.