Similar to Werewolf, one of the decisions you'll want to consider around getting your first combat skill to level 50 is if you are interested in all the benefits that come with being a Druid. Druid's combat skill is one of the nicer for its damage-over-time (DoT) and comes with a lot of versatility, Druid also works with a lot of animal forms, and the Druid travel options are considerably powerful. To become a Druid, you'll need to use the altar near the big tree in Sun Vale once you have level 50 in any other combat skill.

The main drawback is also pretty light compared to, say, Werewolf. You cannot get XP in anything other than Druid while a Druid event is taking place. This originally seemed like it would be a pretty big drawback, but considering the benefits and the fact there always seems to be Druids online to clear mobs, I don't think you hear many Druids complaining about it. Druid, unlike Werewolf, may actually be a skill you want to take on your main character given these benefits, but keep in mind that you will be obligated to participate in Druid events. You also need to use wood weapons to utilize your Druid combat skills effectively, meaning some combos like Sword/Druid aren't really possible. Others, like Hammer/Druid are possible, but require using wooden clubs instead of metal hammers.

One of the other things that makes Druid kind of attractive is that you can take advantage of Deer form without having to spend resources or time otherwise to turn back into a Human when you need or want to. If you want to test out animal forms without committing to being a full-time animal, Druid is a good way to do that.

Please note, I do not play a Druid, so it's possible something here might not be accurate, I'd recommend asking an existing Druid more about the limitations before making any major decisions on your main character.