How do I even start experimenting with different tones/effects?

Hello fellow guitarists,

I've been playing for quite a long time now but when it comes to my tone I've always been lazy to try new stuff. I just plug my guitar on my mediocre amp and play without any pedals, just the built in distortion (I play metal btw). I'm always jealous of a nice tone when I hear it, but I really don't know how to go into that direction.

My idea is to find a solution that allows me to try many different tones, experiment and, hopefully, find a tone that I like.

What would you suggest? A guitar interface or a pedal board? I'm looking for something that comes bundled with many different models/effects etc. My budget is up to 300 USD/EUR.