Why can't I connect to postgres?

I just installed Postgres for Mac.

Also, where is a nice browser/editor for postgres? Something like the
OpenBase manager, but for Postgres. Something friendly and neat and
simple. I'm sick of all these stupid syntax errors making me spend
half a day doing something I could do in 1 minute.

I tried SyBrowserX, but it wouldn't connect. I tried an SQL browser
that I wrote myself in REALbasic, and it also wouldn't connect. Why
can't I connect to postgres??

I haven't got very far and yet I'm already seeing problems. I'm
assuming there's a simple solution.

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