Gilbey.
I'm pleased to see your philosophy studies have homed in on one of the key issues. I have written quite a lot on "existence" on A2K, but at this time I would simply advise you
(1) to consider how the verb "to be" is handled in other languages like Spanish for example (1st link)
(2) to get an overview of various philosophical aspects of "existence" and "being" (2nd link),
and (3) keep well away from the word "mind" because it may "do your head in" if you encounter the vast literature on "consciousness" too early.
http://www.studyspanish.com/lessons/serest1.htm
which serves as an introduction to
http://www.formalontology.it/being.htm
