One thing about planning, it prevents you from wasting money on "stuff" that will not fit on your railroad when finally built. If you look around this forum and other model railroad forums, you will find that most model railroads fall into one of several classes; 1. ovals (folded and otherwise), 2. dog-bones (also folded and otherwise), 3. out and backs (a yard on one end with a main line run that ends with a reversing loop), 4. double ended reverse loops, and 5. variations of point-to-point. All of these topics, and many others, are discussed in John Armstrong's Planning for Realistic Operation book which is readily available.
As others have said, nobody can give you an idea of what you want. You have to read, look at examples and then decide what you want. Then, find a way (invest in a cheap windows laptop (maybe even used) and use free software) to get your idea into an easily viewed image where constructive comments can be made by assisters. The nice thing about planning software is that it allows you to "build" using the track type (FasTrack, Atlas, whatever) you have, or plan to buy, and see how well it will all work out.
Chuck
