Start with simple things, I'm sure what you have in your grocery store will be plenty to expiriment. After years of experimenting, I went back to simple things like paprika, parsley, dill, caynne pepper, brown sugar, yes I use brow sugar too when season meats. Those are the things I use the most. Yes I use oregano and rosemary, all spice and cloves, cinnamon and citric acid, cumin and fajita seasoning, orange and lemon peel (thouse you do not have to buy, you can dry them your self), bay leave and cilantro ... but really the main things are those few that I use all the time.
You are what you eat.