That’s a pretty tall order. I’ll take a crack at it. Realize there is only so much room allowed in a single post, and there is always more to learn, so this is by no means a ‘final’ answer, rather a beginning.
1.) Prayer is nothing more than conversation with God. Sometimes we use ‘standard’ prayers (Such as the “Our Father” or “Hail Mary”) Other times we simply speak to God from the heart, about anything and everything. We give thanks for the things we have, we pray for the health of others, we pray for souls in purgatory. We give praise. We lay our problems before Him and ask for help. Above someone mentioned speaking to the Lord as though he was sitting next to you. That’s as good a place to start as any.
2.) Saints are souls that we know are already in heaven. Not everyone gets a straight path to the heavenly kingdom. Some have to spend time in purgatory. Others may have to wait for judgement. Because Saints are already in heaven, they can hear our prayers, intercede for us, and give aid to those of us still on earth. Basically they are friends who we talk to and ask for prayers.
3.) The Holy Ghost (aka Holy Spirit) is the third member of the Holy Trinity, and plays a vital role through the Old and New Testament. (See the story of Pentecost, when the Holy Spirit descended upon the disciples and filled them)
4.) Sacraments are tools that help us spiritually. The seven are: Baptism, Confirmation, Eucharist, Penance, Anointing of the Sick, Matrimony, and Holy Orders. I’ll let you google to find out more about each one, as I’m trying to keep this reasonably short.
5.)The Holy Rosary is many things, actually. In a way, it is the entire story of our salvation, but I’ll try to keep this simple. A rosary is a string of beads used for praying and meditation. It is also the prayer itself. So I can pick up my rosary from the table, and then kneel and pray a rosary. As a person prays, they reflect upon certain mysteries. I could talk about the rosary all day, but that’s the absolute basics of it. There are plenty of books and websites that you can visit to learn more, and I hope you do.
6.) I’ll leave the question of heaven to someone more qualified.
7.) The Catechism is a declaration of beliefs of the Catholic Church. It is based upon 2000+ years of careful study, interpretation, and tradition going all the way back to the first century. Most Catholics have a copy of the Catechism in their bookshelf, because if you come up with a question about “What does the Church say in this matter?” you can look it up.
8.) You should be able to attend whichever Church you choose (anyone else can correct me if I’m wrong. I’m still new to the Church, but I don’t believe there should be any issues with relocating down the street)
Again, these are short answers to very DEEP questions. You could literally write a book on any one of these topics and still not cover everything, but that should be enough to get you started on learning more. Hope it helped.