As an Spanish I must admit I'm not very familiar to how you learn our grammar and the terms "present progressive" and "regular present" were complete strangers to me until 2 minutes ago that I googled it.
If I'm not mislead you ask for the difference between "Andar/Ando" and "Andando"
Well it's pretty much the same as "I walk" and "I am walking"
The regular present is used for daily basis actions or general expressions that are "commonly true". For example: Yo ando todos los días para ir a clase.
The present progressive is used to express and action that is taking place in that exact moment. For example: Ahora mismo estoy andando para ir a clase.
Hope this helps, though I know I'm kinda late to answer and probably you sorted it out long ago