Can I invest in an index fund if I'm 18 but don't have a job yet?

I'm an 18 yo college student, and after paying for all of this semester's tuition, books, laptop, etc. I'm left with a $1,050 check from scholarships. Since I already have everything I need right now, I was thinking about putting half the money into an ETF like SPY and the other half in a few low cost index funds. I'm assuming the money can eventually be used as a down payment on a mortgage when I'm in my 30s or just for emergencies. The problem is that I don't have a job yet.

Will they require me to have a job first, or am I already eligible to start an account?

What are the requirements to start an account?

Also, where do I go to start the account? Scottrade? Edward Jones?

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