Guild Wars 2

I have had GW2 for a while, but never really had time to play it. Been working on a guardian now that I have some free time and am enjoying it. I try to keep one of each weapon that the Guardian can use on me at all times, but I am having trouble figuring out the roles of the various weapons. I don’t know their purposes/different usages; in other words, when to use what weapon. I usually use hammer for soloing, or sometimes switch to greatsword just to mix it up. I am guessing that staff is for more of a support role? I use it sometimes for escort quests or group quests. Also no clue as to when to use scepter, except maybe to “pull” a mob from a distance? I am still clueless as the difference between using a sword vs using a mace. Or, using a sword/shield vs, sword/focus vs. sword/torch. (or mace and any of those combinations).
I am a complete noob and totally lost, so if any of you guys could enlighten me, I would greatly appreciate it.

I am new to GW2 (and relatively new to MMOs) and am looking for a a casual guild. , preferably of 20+ year olds. I am mainly looking to chat and learn about the game right now, with an interest in PvP/WvW later on, once I level.

I am a North American player, on the Crystal Desert server.

My main is a lowbie Norn Guardian.