Breathe for the Freestyle Stroke

Many people think that you are actually supposed to hold your breath while swimming, but this is actually wrong.

Steps

Turn your head to breath while swimming as usual.
Take in as big a breath as you can in the short moment you turn your head, short enough that people cannot find out you are breathing. When your right hand is getting out of water move your head sideways to the right and take a breath. Always take breath from on side either right or left. Breath after every two strokes so that your body gets constant energy.
Once your face is back down in the water don't hold your breath, instead slowly breath out through your nose. When your head is underwater exhaling (blow air) through your nose and keeps facing downwards for smooth movement while moving your head to breath. Then repeat the process
Once you can no longer breath out, and you have done your two strokes, turn your head sideways to take in another breath again.
Continue this process.

At first you may only be able to do two strokes, but over time this will start to improve.
Try this out of the water as well as in water i.e. fill your lungs within one second and empty it over 20 seconds, then try 30 seconds and so on.
Practice your breathing. Breath in for 5 seconds, hold your breath for 5 seconds, then blow a steady stream of air out through your mouth for 5 seconds. Then try doing it for 10-15 seconds.

Remember taking in massive breaths can cause you to go lightheaded, stop practicing once this happens, it can cause brain damage if you continue.