A few short tips.

     If  you  keep  failing  to defeat early raiders, the try and keep
your town garrisoned, for a greater success.

     Checking  your  Diplomatic Relations Chart, on regular occasions,
will help you knwo where your battling empires are, and enable you not
to get involved in ana alliance that will se you get several automatic
enemies.

     Only  build  military  units  to  a size your economy can handle,
unless you mass them for a quick strike against some wealthy opponent.