To avoid the fight with Elder Wyrm in the Golmore Jungle, do the following. Ride a Chocobo in front of the Henne Mines, but bear south through The Feywood as soon as you enter Golmore Jungle instead of taking any other routes (the Chocobo will allow you to avoid fights with enemies here that are likely too strong for you to yet handle). By riding the Chocobo and avoiding fights, you can easily get to the entrance of Bur-Omisace without having to yet battle the Elder Wyrm.