I'm actually trying to install odoo 11.0 on macOS High Sierra. I've followed the documentation, but when I go on my localhost:8069, I obtain an error 500 (internal servor error). A bunch of lines appear in my terminal, with an error :

2018-05-03 12:13:50,223 23484 ERROR ? werkzeug: Error on request:
Traceback (most recent call last):
  File "/Users/amandine/odoo-env/lib/python3.6/site-packages/werkzeug/serving.py", line 205, in run_wsgi
    execute(self.server.app)
  File "/Users/amandine/odoo-env/lib/python3.6/site-packages/werkzeug/serving.py", line 193, in execute
    application_iter = app(environ, start_response)
  File "/Users/amandine/odoo/odoo/service/server.py", line 252, in app
    return self.app(e, s)
  File "/Users/amandine/odoo/odoo/service/wsgi_server.py", line 166, in application
    return application_unproxied(environ, start_response)
  File "/Users/amandine/odoo/odoo/service/wsgi_server.py", line 154, in application_unproxied
    result = handler(environ, start_response)
  File "/Users/amandine/odoo/odoo/http.py", line 1316, in __call__
    return self.dispatch(environ, start_response)
  File "/Users/amandine/odoo/odoo/http.py", line 1290, in __call__
    return self.app(environ, start_wrapped)
  File "/Users/amandine/odoo-env/lib/python3.6/site-packages/werkzeug/wsgi.py", line 599, in __call__
    return self.app(environ, start_response)
  File "/Users/amandine/odoo/odoo/http.py", line 1445, in dispatch
    self.setup_db(httprequest)
  File "/Users/amandine/odoo/odoo/http.py", line 1377, in setup_db
    httprequest.session.db = db_monodb(httprequest)
  File "/Users/amandine/odoo/odoo/http.py", line 1528, in db_monodb
    dbs = db_list(True, httprequest)
  File "/Users/amandine/odoo/odoo/http.py", line 1496, in db_list
    dbs = odoo.service.db.list_dbs(force)
  File "/Users/amandine/odoo/odoo/service/db.py", line 366, in list_dbs
    with closing(db.cursor()) as cr:
  File "/Users/amandine/odoo/odoo/sql_db.py", line 634, in cursor
    return Cursor(self.__pool, self.dbname, self.dsn, serialized=serialized)
  File "/Users/amandine/odoo/odoo/sql_db.py", line 178, in __init__
    self._cnx = pool.borrow(dsn)
  File "/Users/amandine/odoo/odoo/sql_db.py", line 517, in _locked
    return fun(self, *args, **kwargs)
  File "/Users/amandine/odoo/odoo/sql_db.py", line 585, in borrow
    **connection_info)
  File "/Users/amandine/odoo-env/lib/python3.6/site-packages/psycopg2/__init__.py", line 130, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"?

Looking at it, I thought PGSQL wasn't installed on my computer, so I tried to use the "psql" command, and I obtained pretty much the same thing.

psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"?

I tried to install psql from scratch using homebrew with 

brew install postgresql

Warning: postgresql 10.3 is already installed and up-to-date
To reinstall 10.3, run `brew reinstall postgresql`

And, well, that's pretty much it, i'm kinda clueless now.