Thoughts are the most powerful force on the earth. Everything, right from the mode of transport to medium of communication is because somebody has thought of it. You need to train your mind to derive maximum benefit out of it by producing useful thoughts.
Generally, our mind is so busy in multi-tasking and keeping tracks of various inputs that it hardly gets time to produce meaningful thought. In other words, there are lots of distractions available in-front of mind, which keep it remain at shallow level and waste energy in fluctuations from one thought to another.
To train your mind requires reducing the distractions and applying physical, mental and spiritual methods to stop that so-called "internal dialogue" and go deeper level of mind. Lack of finances to meet the basic requirement of life and clutter in environment are major distractions. So you should work to fulfill your daily requirement and make your environment clutter free first.
Further, to train your mind to keep its attention totally dedicated to certain thing requires constant practice and adopting proper training. Physical exercise like jogging, breathing, stretching is a good way to start up while mental methods like concentration, detachment, etc. advance you, to some extent, and spiritual method like meditation and faith in Super Power help you to have trained mind.
Finally, be conscious of what's happening in you and outside. With regular practice, the mind get's trained to remain in the deeper level and help you to produce useful thoughts. As you go deeper, you start to enter the calmer and more peaceful state of mind.