YOU SAID:

started out just drinking beer, I didn't know why or how I got here.

INTO JAPANESE

ビールを飲み始めただけで、なぜ、どうやってここに来たのか分かりませんでした。

BACK INTO ENGLISH

I just started drinking beer and didn't know why and how I came here.

INTO JAPANESE

私はちょうどビールを飲み始め、なぜ、どのように私がここに来たのか分かりませんでした。

BACK INTO ENGLISH

I just started drinking beer and didn't know why and how I came here.