Many Eastern European gadolim such as R' Yaakov Kamentsky were heard to comment on numerous occasions how the German traditions were the most authentic. After the destruction of the 2nd Temple, many Jews were taken as slaves to Italy, where eventually they found their way to freedom and built communities. Their customs stayed close to those of the Holy Land with which the leaders of the communities kept close communication. This continued as they migrated north to the Rhine Valley in present day Germany. The German Jews, or Ashenazim as they came to be called, continued with close communication to Israel and Bavel and were meticulous about preservation of custom.
After several hundred years, Jews migrated east to Eastern Europe and it was there that many practices changed in part because communication with sages in the Middle East became difficult, in part because of the conditions of extreme poverty, in part because of the rise of the Chassidic movement and its adoption of elements of Sephardic and mystical practice, and likely for other reasons as well.
Basic Ashkenazi practice whether it be Polish or Lithuanian or even Chassidic finds its origins and structure in minhag Ashkenaz. However, many of the original practices are kept only by German communities. One example is washing before kiddush. Another is a single person saying mourner's kaddish. Another is saying birchos hatorah before korbanos rather than at the start of schacharis. There are several practices that are kept both by German Jews and Sephardim as both have kept the original practice. Boys wearing tallis is an example of this.
Some practices spread from Ashkenaz to the entire Jewish world. For example, did you know that the phrase "baruch hu v'baruch shemo," said while others make blessings for themselves (said after Hashem's name) is a German Jewish custom?
German practice is not wildly different from any other, but is, in of itself, very beautiful and noble Judaism. There is a particular stress on dignity, sanctity, and community. As an example of the latter, tehillim on Friday night are recited responsively, with the schliach hatzibur reciting a line and the congregation reciting the next line.
Fortunately for you, you don't need to rely on me for coverage of minhag Ashkenaz. There happens to be an institute that is dedicated to the preservation of minhag Ashkenaz. The Institute is headed by a R' Shlomo Benyamin Hamburger, a profound scholar who R' Chaim Scheinberg referred to as a gadol on the subject of minhagim. He lives in Bnei Brak and writes in Hebrew but happens to be fluent in English. A number of other scholars work with the institute and they publish a yearly hard cover journal, have produced a series of volumes on German minhag, and maintain a website which covers the subject in English.
The best way to experience minhag Ashkenaz is in a German Jewish minyan such as that at Kehillas Adas Yeshurun in Manhattan in Washington Heights, near Yeshiva University, at KAJ in Jerusalem (Ramot), at KAJ Monsey, New York, or at Kiriyat Sefer in Israel. There you'll see the special approach to tefillah and to the beis kenneses. And then for minhagim of the home, you'll need to experience the minhag Ashkenaz home.
As we have explained, a person can study the writings of Rav Hirsch without taking on German Jewish custom. Much of the Jewish world does that, from Yemenites to Bubover Chassidim. You can even primarily follow the derech of Torah Im Derech Eretz without taking on German minhagim. They are both beautiful gifts from German Jewish Orthodoxy.
And you can do the reverse as well. You can take on German minhagim without following the derech of Torah Im Derech Eretz. Rav Hamburger, while having enormous respect for Rav Hirch, does not maintain a TIDE derecch.
As for non yekkes taking on the German practices, Ashenazi Jews can rely on poskim who permit this on the grounds that these were the original practices. Baalei teshuvah who cannot identify family practice have a particularly strong case for the switch. I can put you in touch with rabbanim for further discussion.
This video of the Menhorah lighting at KAJ in Washington Heights, gives a sense of the decorum of the German approach. Lighting the Menorah at KAJ