Many people use needle threaders to thread needles. There are a variety of types available. The simplest of these is available in sewing departments in most cities. It consists of a small piece of metal with a wire loop attached. With a little practice the process can be done quickly and easily.
Many people also like to use self-threading needles.
For hand sewing, these needles are widely available, but self-threading machine needles are more difficult to find. Either means of threading needles is workable. Most sewing machines come equipped with a seam guide to be screwed onto the machine table to the right of the presser foot. These guides can generally be purchased separately if desired, and other types of guides are also available. Some blind people like to put tape on their machines as guides.