Hey athlegan, thanks so much for being supportive and for the advice.
I've been researching more about this and I need to get a certification. I've spent all day trying to decide which one I'll go for. This article has helped me though to have a clearer idea > http://www.ptpioneer.com/best-personal- ... ion-guide/
I'll follow your advice and go check with nearby gyms to see how I can get started, or if they'd allow me to train people after I have the certification
Also, starting on it as a side job seems more clever, right?