Contracting is a field with very vast potential. You can start taking small contracts from people whom you know. i.e. renovation, roofing etc. Once you get sufficient experience you should try to get the government license class E. For that you need to give security deposit. Hence, you can start eventually working. Further, you can also take subcontracts. I suggest you to visit sites around you before taking work directly, so you will be able to know the activities and problems that are faced during the construction.