First off (and this is pretty much something every player needs to have) you should get atleast 10 exploration.
Then go foraging and find a WWW (Wild Windsown Weed), dry it on a herbalist table if you have access to one, otherwise a Drying Frame works aswell.
Once the weed is done drying, it should have turned into a random plant seed, could be carrot, grapes, wheat, or if you're lucky - flax.
Getting most of the seeds as early as possible is definetly an advantage.
For more information, see
http://havenandhearth.wikia.com/wiki/Wild_Windsown_Weed and
http://havenandhearth.wikia.com/wiki/Farming .
Good luck!