@Manuel Sandoval , My advice is to pursue the construction field. Even if you start out cleaning up job sites. It will allow you to save up some cash and it will give you some of the knowledge and experience that you will need. If your plan is to get a really old house, you are going to have to know how to fix it.
The fact that you live in a really poor city does not mean that you can't pursue a career in real estate. In fact, I think you should use it to your advantage. There are some people out there with money and investing potential that might not have any connections to the low income city. If you can become somewhat of an expert in your location and be a pointman for an outside investor, perhaps you can make yourself an important and useful tool for someone that does have the capital to take a chance in the city. You can be the person to oversee the projects in the city or you could be lining up all the renters or connecting with all the contacts, etc. Then you eventually build up enough money and connections to fund projects yourself.
You are ahead of the game because you already found something that interested you, now find a way to make yourself valuable to others in the industry that could partner up with you.
Good luck and go get 'em!