have you kept pigs before? if not get some weaners then reevaluate after a year or so.
i could say an acre isnt enough for breeding pigs 24/7 but many are raised for less ground so it depends on how it is managed, ground, worming, poo picking, whether they are in during winter etc whether you sell as weaners, or keep some on to finishing for yourself, whether you have to house a boar.
its very hard to make a profit.
weaners are much more fun and less risky. maybe get in a group of them and see if you have a market for meat near you. then the ground is rested when they have gone.