Is there a general marker blood test for cancer that can tell if there is any kind of cancer in the body?

Mostly no: There are a few cancers that can be diagnosed by a blood test, e.g. leukemia, and multiple myeloma. There is no single test for cancer in general. Have a healthy diet, exercise 30 minutes/day, drink plenty of water, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/. Wish you good health!