There are as many opening styles and gambiys when you start learning as there are after more experiance. My only comment at your very early stage is dont get put off if you went in "feet first" on suicidal (some do - crazy people
) and got blown away like a piece of loose flotsum amidst the ravaging demons from hell descending on you .....
Use the lower levels as a learning experience - they give you time to react and think about the basics and Strategy, as the AI gets crippled on the lower levels - On Cakewalk for example, the AI just about manages to say "ga-ga" and dribbles profusely, cant do much else!
A few do go in at Suicidal and are fine, the remainder of us mere mortals stepped up slowly through the difficulty levels, learning as we went along. The problem going in at too high a level to start with, is you spend your time trying to stop being overrun by rampant civilisations, and not enough time learning what you should be doing to stop them descending on you in the first place.
Takes a few weeks/months to really get Good at it, persevere, its great fun.