This is not a complete set of instructions. You can read how to change a moped tire in most manuals. This is an additional item, very often overlooked that needs mentioning.
Left, a tire has just been mounted on the rim. Before air is added, the area near the valve stem is checked. Sure enough, the tube is pinched between the tire and the rim. If ignored, this will cause a bulge in that area.
Right, the same tire after pushing the valve stem up inside the tire. Now the tire will be straight when inflated. Pushing the valve stem inside the tire before the final mounting will also make the mounting easier, since the pinched inner tube is making the tire tighter on the rim on the opposite side. When your tires are mounted correctly, smooth roads will not feel like bumpy ones, and your bike will feel solid, smooth, and more enjoyable.