Sewing patterns usually have two sheets of guides and instructions included with the tissue-paper pattern. The guides will tell you what abbreviations mean, which pattern pieces to use for each pattern view, show pattern layouts for each view with two different fabric widths (usually 44-inch and 60-inch wide fabric) and give cutting and sewing tips. The instructions will give you step-by-step descriptions of preparing and sewing each piece.
After you've decided which view to make, look at the guide to see which pieces you'll need. Cut out those pieces, which are usually lettered, and press them with a warm iron. Pin them to the fabric as shown in the layout guide, or use weights to hold them in place, and cut them out on the cutting line. The cutting line is not the seam line, so be sure you're looking at the correct one.
Follow the instructions to assemble the garment or other item you're making. If you have trouble understanding the illustrations in the instructions, there are plenty of basic sewing lessons online.