That engine needs fuel, compression and spark to start and run. You are missing one of those.
Read the first answer here:Where_can_you_find_a_1993_Subaru_Legacy_engine_diagramThere are Haynes and\or Chiltons guide for every Subaru Legacy\Outback to 2005(US Models) you can find the specific one you need on www.haynes.com they have engine and body diagrams.
The starter is located on the right hand side of the engine near the bottom. You can follow the positive battery cable from the battery to the starter.
A 2002 Subaru Legacy uses standard 10w-30 weight motor oil. During the winter, a lighter weight oil may be desirable in particularly harsh locations.
the red one
The 2003 Subaru thermostat is located inside of the thermostat housing, on the front of the engine. The thermostat will be near the bottom of the engine.
The 2003 Subaru Legacy has a flat 4 engine.
The 2012 Subaru Legacy has a flat 4 engine.
The 2007 Subaru Legacy has a flat 4 engine.
The 2002 Subaru Legacy has a flat 4 engine.
The 2001 Subaru Legacy has a flat 4 engine.
The 2014 Subaru Legacy has a flat 4 engine.
The 2009 Subaru Legacy has a flat 4 engine.
The 2013 Subaru Legacy has a flat 4 engine.
The 2010 Subaru Legacy has a flat 4 engine.
The 2005 Subaru Legacy has a flat 4 engine.
The 2008 Subaru Legacy has a flat 4 engine.
The 2006 Subaru Legacy has a flat 4 engine.