I feel like they're related in technique but have fundamentally different results. Pickling can enhance and sharpen flavours but fermentation, at least the salt anerobic kind, tends to mellow flavours. I found it helped to start with some pretty simple stuff. Just a single ingredient and salt (and water). It's Alive, the old Bon Apetit (booo!) show, has some really helpful starting recipies. Noma's guide to fermentation really emboldened my fermentation choices.

I got one of those fermentation kits of Amazon that has a couple of jar lids with a one-way valve, some glass fermentation weights, and a large syringe to pull air from the jar. I was much less worried about turning something poison with the added help from those tools.

My process is usually when something is going to go bad I put it in a jar I know the weight of, add a spice or something that may taste good then add water. Then weight it and calculate 2.5% salt of the item+spice+water. You can go lower than 2.5% but that's a pretty safe number. Then I'll look at it and taste it a couple weeks in, decide if it needs more time and keep going. Some things have a tipping point where all of a sudden they taste really different. Other things have a more linear progression.

Experiment and have fun!