I cant give you practical guidelines to a "successful" life. What is "success". How many "successful" people are unhappy. How many "unsuccessful" people are...happy, but you dont hear about them.
I can give you practical guidelines to a happy life tho, not to confuse with a life of pleasures. A happy life is a balance of healthy pleasures supervised by a strong , stable faith which requires being maintained, trained constantly, which is obtained by giving as much as you receive using the maximum of your best capacities in the interest of others as much as yours.
If your faith has been destroyed by others, take your distance from them without any remorse, and listen directly to God 's words he left us in the Bible so we can make proper use of our mind/soul and body, because He is our creator, He is the father of every single man, woman , kid on earth. His words are the path to Life, this is why He is called the Living God. He will teach you love, loyalty and fidelity. He will guide you to having children, and then you ll be ready to understand the others 50 % of life a single man or woman doesnt know.
But for a partially lost atheist, it would require reprogramming thought patterns, behaviors, habits, relationships. It requires modifying your mind, just the way you modify, sculpt your body. Keeping the good, and getting rid of the bad.
I have a blog written in french which is quite huge and well followed by french speaking people, and most of what i write on here once in a while is a translation of what i write there.
God's words have been powerful enough for long enough to allow countless generations of men and women to maintain protect and develop life, so my modest participation , which can be understood as a modern reinterpretation of the message of God, as useful as it obviously is to some who still have enough faith left in this lost world and who want to preserve and cultivate it, couldnt replace God's words.
A mix of both should be prefered. Faith is a personal experience, but we re all walking ont he same path, we re just at differents steps.
Hopefully one day my english skills will be good enough to translate everything i wrote in french to english, or maybe someone's else will do it.
A good first step would be to buy a Bible, ignore all the people who didnt read it -following their own parents "advises", ignore all of those who made a false interpretation of it or who tainted its message with their own sins, and make your mind all by yourself. Without guidance we are nothing and we get lost. We can make good use of our souls and bodies only by following God's words. Atheist fall into despair after believing in nihislm, and absurdity. As a result they dont reproduce or destroy their kids by abandonning them, or convert to islam.
As Esaie said it "those who dont believe, wont survive".
Our future is a mix of the best from past and present. And we have to filter with the use of faith good and bad. Intelligence, money, "strenght", without a heart nourrished by a constant faith, by spirituality, are useless at best, destructive most of the time.