New Player - Concerns

Leveling alone is no problem at all, you can play the game like a single player game to level 80 (and a little bit beyond that) if you want to but since AoC is a MMORPG the main focus lies on doing group content, especially on level 80 where you will have the biggest variety of dungeons to choose from.

Joining a guild might be the most useful thing you can do since there is a lot to explain, not only for the mechanics of the game itself (like where to travel to other areas, how to pick talents and so on, daily challanges) but also for the classes, the faction choices on level 80 and the mechanics in the dungeons and raids itself. Obviously, you should join a “beginner-friendly” guild, not one of the “elite” guilds that only do hardcore raiding but there are far more beginner-friendly around so you can easily choose one you like.

There are a few guides in these forums right here (Compiled list of useful guides for Age of Conan) but as Trax already said, the old forums (http://forums-archive.ageofconan.com/forum.php) got a lot more content (that is still up to date for the most part) because it just older.

I would just suggest you to try the game since you don’t want to rush to level 80, play a few classes to level ~40 since on the lower level they play very similar or just stay with the one you chose if it’s fun. All classes are equally needed on level 80, especially since class stacking is no problem and other people can probably switch to something that is needed.