5. Encourage those who are doing good. This is not limited to pastors, although it is certainly true for them. Nothing is rarer than hearty thanks, and you probably will never know how much your thanks, praise, and encouragement means to those who get it. Whenever you can, of course, you should seek to educate and correct those who are erring. But never forget to praise those who are on the right track. All of us get discouraged in doing good; that's why St. Paul writes (Gal. 6.9) to let us not be weary in well doing: for in due season we shall reap, if we faint not."
6. Participate wholeheartedly in church. The main thing here is the Mass: listen attentively, sing wholeheartedly, and pray without ceasing. Pray for those around you, and pray for the pastor doing the service. But participate in other things as you are able: teach Sunday school, work with the youth, visit the sick, "whatsoever thy hand findeth to do, do it with thy might." (Eccles. 9.10) We all have limits on time, and most of us have family responsibilities and work that has to be done. So pick judiciously, do what you are good at it, but help in the task of God's church.
7. Don't gossip. It's easy to do, but there are few things as corrosive as gossip, few as damaging to God's church. When someone starts to tell you something bad, ask if they have talked to the individual. And even if they have, ask them what purpose is served in telling you. Keep short accounts. It's easy for us to damage our relationships with our brothers and sisters in Christ, and we need each other.
8. Forgive, and be forgiven. We stand in constant, daily need of God's forgiveness. So forgive quickly, and be quick to receive God's forgiveness. One of the most insidious violations of the first commandment is to make ourselves our own God by thinking that we have no need of forgiveness from God, that we must somehow make ourselves better before we come to God. Christ died for sinners -- don't seek, no matter how important you think you are, to be too good to be forgiven. Virtually no one makes use of private confession and absolution, but this is as good a time to start as any. Go to your pastor, and ask to make confession. Very likely, your pastor will be new to this, too, but both of you can learn. Use the order for private confession, and confess your sins. This is not for the "big" sins (although it's for them, too): it's for all sins that are troubling you. Confess them, and be assured of God's forgiveness.
9. Make use of the means of grace. You are baptized, so remember your baptism daily, and make the sign of the holy cross. Receive Christ's Body and Blood frequently for your forgiveness. The faith you have been given is not some kind of intellectual exercise: your Savior gives you His Body and Blood. Rejoice in that gift, thank God for that gift, and be blessed in the mercies of God your Savior.