The word "kosher," which describes food that meets the standards of kashrut, is also often used to describe ritual objects that are made in accordance with Jewish law and are fit for ritual use. Food that is not kosher is referred to as treif.
Kosher is not a style of cooking and therefore there is no such thing as "kosher-style" food. Any kind of food - Chinese, Mexican, Indian, etc. - can be kosher if it is prepared in accordance with Jewish law.
At the same time, traditionalJewish foods like knishes, bagels, blintzes and matzah ball soup can all be treif if not prepared in accordance with Jewish law.
Keeping kosher is not particularly difficult in and of itself; what makes keeping kosher difficult is the fact that the rest of the world does not do so.
The basic underlying rules are fairly simple. If you buy your meat at a kosher butcher and buy only kosher certified products at the market, the only thing you need to think about is the separation of meat and dairy.
Keeping kosher only becomes difficult when you try to eat in a non-kosher restaurant or at the home of a person who does not keep kosher. In those situations, your lack of knowledge about your host's ingredients and the food preparation techniques make it very difficult to keep kosher. Although the details of kashrut are extensive, the laws all derive from a few fairly simple.