Welcome to Mi Yodeya.

Your question is a big one (meaning that to really answer properly, would require a very long response). But with that said, hopefully, you will find this helpful.

You open your question by asking, "How do you become a Baal Teshuvah?"

For many, this specific term (in English, someone who has mastered the process of returning to G-d) has a particular meaning relating to someone who is working on themselves to correct some kind of transgression either against G-d, or their fellow human beings, or both and has completed that work. This concept is discussed in many places, but one clearly worded place discussing it is in Rambam's Mishneh Torah, Laws of Teshuvah, Chapter 2, Law 1.

But reading the balance of your question indicates that you mean this in a more general sense. That you are trying to learn more about what it means to incorporate traditional Jewish observance into your life on a daily basis. And that is a very big question indeed!

While agreeing with all the good recommendations already offered by mbloch in the first answer, I would suggest that you might find the following very helpful because of its broadly encompassing nature.

Rambam, Rabbi Moshe ben Maimon, wrote an all encompassing book dealing precisely with the subject of your very big question entitled Mishneh Torah.

Rambam himself wrote in his introduction to this book that any Jew who used his book would not require any other resource to know what was required to live a traditional Jewish life.

Therefore, have I, Moses son of Maimon, of Spain, girded up my loins, and, supporting myself upon the Rock, blessed be He, made a comprehensive study of all those books and minded myself to construct out of all these compilations a clear summary on the subject of that which is forbidden or permitted, defiled or clean along with the other laws of the Torah, the whole scope in pure language and concise style, so that the Oral Torah be entirely methodical in the mouth of everybody, without query and without repartee, without the contentious thus of one and such of another, but clear text, cohesive, correct, in harmony with the law which is defined out of all these existing compilations and commentaries from the days of our Holy Master till now; so that all laws be open to young and old, whether they be laws concerning each and every commandment or whether they be laws concerning matters instituted by scholars and prophets. The main object of the matter being, that no man shall have a need of any other compilation in the world for any law of the laws of Israel, but this compilation shall be a cyclopedia of the whole Oral Torah together with a code of the statutes, customs and edicts which were enacted since the days of Moses our Master until the close of the Talmud, even as they were interpreted for us by the Gaonim in all their compilations which were compiled by them since the Talmudic era. Therefore, have I named this compilation Mishneh Torah; for, when one studies Holy Writ first and thereafter reads this Work, he obtains herefrom a complete knowledge of the Oral Torah, having no need to read any other book in between them.

The book is intended to be read in order and each idea presented is built upon what preceeds it. The following link will connect you to the beginning of his overview to the contents of the Mishneh Torah.

May it be a continuous source of inspiration for you in learning how to take on traditional Jewish observance so that you may progress for the rest of your life, going from strength to strength and may it be with joy (Serve G-d with joy!) and without boredom.