Question

How many single covalent bonds are in carbon?

Answer 1

That entirely depends upon the type of compound your carbon is in. See below

Explanation:

There can be zero single bonds, as in `CO_2`; 2 single bonds, as in Formaldehyde or Carbonate ion; or 4 single bonds as in `CH_4`

There are things called carbocations, which can have 3 single bonds. Also, this discussion can get into sigma bonds vs. pi bonds, but the simple version is above.