"Lo siento" would literally be "I'm sorry." You could also say "perdón." If it's an informal situation with someone you're familiar with, you could say "forgive me" with "perdóname" or "perdóneme" for a formal situation. "Todavía estoy aprendiendo español," is "I'm still learning Spanish."
So, I ran into an issue trying to translate today. The concept is that neither one of two people have a certain quality. The specific sentence is "Neither Olivier nor Antonio is Latino." I thought about some possibilities: "Olivier ni Antonio es latino." "Olivier ni Antonio no es latino." "Ni Olivier ni Antonio es latino." Are any of these right, or would it translate completely differently?