The first thing I do getting to the swamps is farm up some entrails from the draugers for sausage. Then go looking around for some turnip seeds.

Once you get the turnip soup and sausages going then start to look for a swamp with crypts for iron.

Typically I will find a small swamp area to farm and leave a portal there with a comfort station just to gather up the entrails and look for the turnip seeds.

Edit add - in larger swamps you will get groups of spawners. Typically 3, two of them being drauger spawners the other one being skeletons. Make sure to destroy them if you can so it makes the swamp a lot easier to search. Initially there are a lot of mobs around but once cleared only a few respawn around. Spawners can be destroyed by arrows but depending on your level it may take a few shots... still typically safer than charging in to clear them. Also the spwaners are around rocks and you often find chests there as well.