Something real happened. Here's what it means, and what to actually do next.
Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new. That's 2 Corinthians 5:17, and it's not a metaphor for trying harder. Something actually changed. The debt sin held over you was paid by Christ on the cross, and the Spirit of God now lives in you. You didn't clean yourself up and then get saved. You got saved, and now the cleaning up happens from the inside out.
That doesn't mean you'll feel different every day, or that the fight against sin is over. It means the outcome is settled. You're not working toward acceptance with God. You're working from it.
One of the most important things now is that you must get into your Bible. Paul says faith cometh by hearing, and hearing by the word of God. That makes it very simple to figure out how to grow. READ the Bible. Jesus said HE is the Word, which means HE is the Bible, and if we want HIM living in us, we must, must read, study, and memorize the Bible. Start here for where to actually begin.
The next most important part is prayer. Without prayer, our relationship with God falls apart. Think about it like a marriage: if a husband and wife seldom talk, do they have a good relationship? Or if the husband talks all the time and the wife never talks, or vice versa. No, we all recognize that as a failing relationship. That is because it is: God wants a relationship with us; He talks to us through the Bible, and we talk to Him through prayer. Here's how to start, honestly.
Don't pick a church that will tickle your ears; find one that challenges you to improve and grow. One where fellowship is alive, and people are excited to come to church to be with others. Encouragement and correction from other believers are what will keep you growing as a believer.
Don't keep it to yourself. That's a good way to cool off. Tell others, and get others excited. Expect to be pushed away from old friends, and expect others to not understand, but that is ok. You have an amazing gift; spread it, share it, tell others!