Simple present: a habitual action: I leave my house in the morning. I work every day; She teaches English.

Also can be a universal truth: the sun rises; the baby cries;

Or even a scheduled event: (it is in the morning and you say to someone) the meeting is 5pm., it was planned for sure.

The third person: the verb takes s/es.

The interrogative/negative: auxiliar: do/does (except for the verb be which is a main/aux verb).

Present continuous: the action started in the past, keep during your conversation and maybe a little while in the future. E.g.: you are talking to someone else and then you say: I am reading a nice book. You started it maybe few days ago but you are still doing it and didn't finished yet. It is formed by sub + be + verb<ing>.

Se utiliza "I am" cuando algo está occuriendo ahora pero tal vez no sea permanente o algo habitual.  Por ejemplo,

I eat an apple every day.  Como una manzana cada día.

I am eating an apple.  Estoy comiendo una manzana ahora mismo.

I live in Ohio.  Vivo en Ohio.  Vivo en Ohio, he vivido en Ohio y pienso seguir viviendo en Ohio.

I am living in Ohio.  Estoy viviendo en Ohio pero solo mientras asisto a la U.

Espero que eso te ayude.  Cuando utilizas presente simple significa que algo ocurre mucho o es regular.

I like tacos.

I run five miles every day.

I go to school at Harvard.

Otros ejemplos del presente progresivo serían:

I am running in a race.

I am thinking about my wife. vs. I think about my wife every day.

I am going to school (I am walking to school right now.)

I go to school on foot.  (Every day I walk to school vs. I am walking to school this one time.)

Espero que entiendas un poco mejor.  Si tienes otras preguntas no hay problema.  :-D