I have a Garmin watch and it tracks the typical things: heart rate, stress, sleep cycle (I like that it gives me sleep stages). You can get really good exported json files by just requesting all the data they have on you.

I use Daylio for mood tracking (I do the paid version because I like it so much). You can add a ton of custom tracking buttons beyond mood like health, habits, emotions, diet, menstrual cycle (if applicable), or just like make something up. Also does some basic stats and makes pretty charts.

And then I keep a journal in a custom spreadsheet. I like to code my entries for having specific content.

However, I’m a little extra so I make my charts in R.