The 12th century offered many opportunites for employment if farming wasn't attractive. The most lucrative was being a mason. This is in the middle of the era of enormous cathedral and abbey building projects and mason and carpenter teams could find steady employment, either locally, or with a short travel. While unskilled labourers received a basic wage, master masons were the celebrities of their day, and could command vast rewards for their work.

Other oppurtunities were in ironwork - every village had a forge, and some areas were famed for extensive industry. The Forest of Dean for instance produced thousands of horse shoes from around 80 forges for royal contracts, and other ironmongery such a nails were in high demand.

Other industry was available, utilising the machinery of water-powered mills that crowded every available stretch of river, often built on specially constructed dams or situated below existing bridges. Not only milling grain for flour, they were employed in fulling cloth, forgework, and making beer as well. Windmills were invented in the late 12th century as well, with the advent of the post-mill, a fabulous invention built on a giant axis which could turn the entire mill easily to face whichever way the wind was blowing. In some areas such as marshes where rivers could not be tapped tidal mills dominated the landscape instead.

If you weren't interested in the various mill industries, the cloth industry would have dominated many regions and towns. Huge factories employed vast quantities of labourers. The pay was controlled by capitalist owners who tightly restricted the market, so it wasn't as lucrative or secure an employment as building work. But places like Flanders were built on clothmaking so much so that when England set up its own textile industry in the late 13th century and banned the export of wool to them their entire economy collapsed and everyone was out of work.

And finally, you could be a miner. While metal mining was available, the biggest mining industry was stone quarrying. All that building work ate up stone, and it can be thought of akin to the 19th century coal industry. While stone was mined everywhere, certain places like Caen in Normandy were famed for their stone production. The modern city of Paris for instance lays on a labyrinth of stone tunnels from this extensive mining industry.

These are the most prolific employment opportunities. There was of course the chance of being a lay brother in a monastery or abbey, getting into merchant trade, seamanship, and military employment, though these were smaller opportunites at the time.

In terms of food, you'd have a pretty good diet that was getting better all the time. The agricultural revolution of the 11th century onwards had invented the three-field system, which encouraged diversification of crops. The invention of the heavy plow was opening up acres of land for tilling that hadn't been able to be plowed before due to the heavy soil. And the invention of the harness for horses allowed this faster animal to plow more field in a day than the teams of oxen previously used. Acreage increased accordingly, and the rapidly expanding agricultural yield allowed by these technological advancements allowed people to eat so well that the next few centuries saw a massive population boom that only ended with the Black Death, after which it took centuries for Europe's population to reach those heights again.

Bread (of various type and quality) and small beer was still your staple, and this would have been eaten at every meal, often with cheese, whey, and eggs. Meat and fish were available, but the big change from earlier centuries were the growth of availability of vegetables which were starting to become easier to get hold of. Beans and peas were showing up on many peasant plates. Even in a 12th century leper clony in Champagne each leper recieved a daily ration of three loaves of bread, a cake, and a measure of peas. Pottage was eaten widely, a sort of stew of grain and whatever other food was available. In most places, but France extensively, wine was ever-present, and consisted of a good third of their expenditure on food.

Source: Gimpel, Jean, The Medieval Machine