ת"שמו is roshei teivos for שמים מעשה תכלית וארץ, "The purpose for the creation of heaven and earth."
The Kotzker zt'l said that we should learn the parshiyos of Shovavim in depth (b’iyun), and perhaps one reason is that Sefer Shemos teaches us the lessons that are מעשה תכלית וארץ שמים, the purpose of creation. The purpose of creation is to know Hashem, and Sefer Shemos, with the miracles that occurred, teaches us that Hashem created and leads the world.
The parashah begins with the words ואלה ישראל בני שמות. The Baal HaTurim writes that the letters of these words are the roshei teivos for the following words: ומדל שרא אדםו נים ש חיהי שירי עיםנ קולב רגוםת אחדו קראמ ניםש סדרה עולם ל רוכיםא בותר, "A person who learns the parashah, twice the pasukim and once the commentary [Onkelos] and sings it with a sweet voice; he will live many, long years." The Gemara (Brachos 8) states, "A person should always complete the parashah, twice the pasuk and once the commentary [Onkelos] together with the community... Whoever does so, his days and years will be lengthened."
But there is also a way to explain this concept allegorically. We read each pasuk of the parashah twice. This represents our life experiences. Sometimes life is pleasurable, and sometimes it is the opposite. However, there is only one targum, one commentary, one way to look at what happens to us, and that is that all situations are for the good. These are among the lessons we learn in Sefer Shemos and this week, in parashas Shemos.
