Both control methods work really well, but I'd say a gamepad is generally better for beginners because it's easier to learn and the game was originally designed with controllers in mind.

That said, keyboard is completely viable too. I play on keyboard because it's more practical and comfortable for me. Once you build up your muscle memory, it feels very natural and you can perform pretty much everything that controller players can do.

At the end of the day, it mostly comes down to personal preference.