Co2 is not needed at least not for everything. Are you looking to start out with easy plants or ??
Anubia, which I answered in another post but you need to tell us what type lighting you have as lighting will determine what type plants you can grow. Anubia are low light tolerant plants.
That is low light so anubia, java ferns both regualar and wendilov, bolbutis, and crypts are what you'll be limited to.
My moss balls do fine with normal old lighting
I've never kept them but always thought they needed at least medium light. Learn something new everyday!