Starting from zero can feel overwhelming, but you’ve got this.
Read. Nothing will help you better then that. Outside of that spend time just writing. Doesn't have to be pretty. Just write. As you do you will develop your own voice. Can be a short tale about dragons or a diary about your day...
Too much of the same kind of showing can get repetitive. Swap some fidgeting for posture shifts, or how he interacts with the space around him. Let some emotions come through in dialogue or what he notices instead.
That's the typical cycle: people get excited about a specific type of movie, studios saturate the market, and eventually people get sick of them and want something different.
Obsidian is great for worldbuilding, although it takes some adjusting to use for writing. However, I think it works well. For worldbuilding, it keeps characters, locations, lore, and everything else organized and easily accessible, and it's extremely easy to search for things.
Just start by outlining broad historical eras (settlement, conflict, stability, etc.). Identify key events, marking them with dates or periods and adding brief descriptions of the important characters or changes that shaped history. Only put what you'll use on the timeline. A lot of this won't...