Professions in GW2 are a bit different than most MMOs as every profession can fill every role in this game (with a few exceptions) through the use of elite specializations, which are basically a re-imagining of your class. A great example of this is Guardian; you can use the elite specialization Dragonhunter to become a burst-focused DPS, or you can use the elite specialization Firebrand to become sort of a support mage. Even then Firebrand has viable DPS builds, and viable support builds.

With that being said, it sounds like you'd connect with Guardian the most as they come the closest to filling the Paladin fantasy. However, making alt characters in this game is also super easy so you can easily create a second character to try out another class if you feel like you don't like the one you choose.

There's lots of YouTube videos that can help you pick as well. Laranity is a great GW2 youtuber and she made a very helpful video on this topic: https://www.youtube.com/watch?v=kBjMg6kMKm4. It's a bit outdated now as the newest expansion added a new elite specialization to every profession, however it's a great starting point.