No credit, bad credit buying car?

Okay… This is an educational guess type Q.
I need a car, I have no credit, my mom has poor credit. We all pay cash.

I was looking at preowned and used… They were around the same price as new.

I feel in love with the 2015 ford fusion se.

Asking piece 23,987.00 After rebates its 18,957.00

My father gets a 15% discount since he works for Union Pasific.

-2,843.55
And college student discount
-500
Now… $15,613.45
And my down payment of 3,500

12,113.45
And the dealer said i may qualify for the "first time buyer" discound too, not sure how much that is.

So, i mean
Would the interest rates be at 15%? With bad credit at 596$ a month?
How does this work

Could a dealership (any) use my income as "credit" replacement? I make 11$ an hour and work fulltime?

Yes i know i should ask the dealer for all of this, and that a new car isnt a good idea since i have no credit and my moms suck -not using my dads since hes still paying iff dome stuff from previous company he owned that ended up going under- but can anyone help on how much IRate might me? Or if a used car at 8,000-10,000 be a best bet?! Ugh.

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