Totally lost with regression equations

Hi I have a dataset of 182 countries and I have to compare them with respect to GDP, energy consumption and Carbon dioxide emissions. How can I compare 3 variables simultaneously together?
Also there are about 3 dummy variables. How do I integrate them into the regression equation?
I am using SPSS.
I have a deadline to comply.
Kindly guide
Thanks and Regards

It might be helpful to better define how you want to compare them. If you're doing a multiple regression model, what is your independent variable?